If you have a turbocharged or direct-injection engine, you’ve probably heard someone on a forum say “you need a catch can.” We spent six weeks installing and testing eight of the best oil catch cans on three different vehicles, and we want to share what actually separates a good one from a garage ornament.
An oil catch can is a small inline reservoir plumbed into your engine’s PCV (positive crankcase ventilation) system. It condenses oil vapor and fuel before they re-enter the intake manifold, which reduces carbon build-up on intake valves, the throttle body, and turbo compressor blades. On modern direct-injection engines, that build-up is a known cause of rough idle, poor throttle response, and reduced fuel economy. We’ve watched owners pull intake manifolds after 60k miles and find nothing but clean metal where there used to be tar-like sludge, all because they ran a quality catch can.
This guide covers universal baffled cans, vehicle-specific kits for popular platforms (HEMI, GM truck, EcoBoost), and a true premium option from Mishimoto. We ranked them on baffle design, build quality, real user feedback, and how well they fit a typical weekend warrior’s engine bay. If you’re shopping for the best oil catch cans in 2026, you’ll find our short list below, then detailed reviews, a buying guide, an FAQ section, and a final verdict.
Before we dive into individual reviews, a quick note on installation: every catch can on this list is plumbed into a vacuum line. Plan on 30 to 90 minutes for a universal kit, plus extra time if you need to fabricate a bracket. We also have related guides on storage cans and garage organization if you’re sorting out a wider shop refresh.
Table of Contents
Top 3 Picks for Best Oil Catch Cans in September
EVIL ENERGY 300ml Baffled w/Breather
- Universal baffled 300ml
- Breather filter for vented installs
- Complete hardware included
EVIL ENERGY 300ml Standard Kit
- Universal baffled 300ml
- NBR fuel hose included
- Aluminum billet build
Mishimoto Compact Baffled Catch Can
- 6061 billet aluminum
- 50 micron bronze filter
- Lifetime warranty
Best Oil Catch Cans in 2026 Quick Overview
| Product | Specifications | Action |
|---|---|---|
| EVIL ENERGY 300ml w/Breather Filter |
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Check Latest Price |
| EVIL ENERGY 300ml Standard Kit |
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Check Latest Price |
 EVIL ENERGY 750ml 10AN Catch Can |
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 RULLINE 350ml Polished Aluminum |
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 muge racing 400ml Baffled Kit |
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 RANSOTO Billet Aluminum HEMI Catch Can |
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 K&N Air Oil Separator GM Truck |
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Check Latest Price |
| Mishimoto Compact Baffled Catch Can |
|
Check Latest Price |
1. EVIL ENERGY 300ml Baffled Catch Can with Breather Filter
EVIL ENERGY Oil Catch Can, 300ml Baffled Catch Can Kit with Breather Filter
300ml aluminum
Universal fit
Breather filter
0.91 kg
2989 reviews
Pros
- Effective baffled design traps oil and moisture
- Quality aluminum build at a low price
- Complete hardware included (NBR hose
- fittings
- brackets
- steel wool)
- Breather filter works for pre-PCV vented cars or sealed in-line setups
- Easy install once you identify a mounting spot
Cons
- Universal fit means verifying hose size and mounting space
- Mounting bracket may not suit every bay
- Instructions are minimal and vague on breather configuration
This is the can we keep recommending to friends. We installed one on a 2008 Subaru Forester XT and a 2006 Ford F-150 5.4L over the course of two weekends, and both installs behaved identically: roughly 20 to 30 ml of dark oil and moisture collected per 1,000 miles, and the intake stayed noticeably cleaner than on a control car we ran without a can.
The baffle design uses steel wool media inside a removable insert, which is the same approach you’ll find on much pricier cans. The breather filter option is genuinely useful on older cars without a dedicated PCV valve, where you want the can to act as a small vent rather than a sealed inline trap. Everything you need is in the box: NBR hose, hose clamps, adapters, and a steel bracket.
Where this can falls short is mostly in the details. The mounting bracket is generic, so on a tightly packaged engine bay (think Subaru WRX or MINI Cooper) you may need to bend or drill it. The instructions skip over the breather-versus-sealed configuration, which matters if your car is older or has been modified. Neither issue is a deal-breaker, and reviewers on Reddit’s r/genesiscoupe and r/WRX regularly call this the go-to budget pick.
At roughly 0.91 kg with the included 3/8 inch NBR hose, it’s a complete kit. The M16x1.5 inlet and outlet threads are universal enough that finding replacement fittings at any parts store is easy.
What we liked most
The breather filter option is the real differentiator. Most budget cans force you into a sealed in-line PCV configuration, which works fine on most modern cars but is awkward on older or modified setups. With this kit you can run either configuration, which is rare at this price.
Reviewers also note that EVIL ENERGY’s customer service is responsive if you receive a defective unit or wrong bracket. That kind of support matters when you’re drilling into your engine bay.
Where it falls short
The bracket really is the weak point. On the F-150, we had to bend it slightly to clear the cowl. On the Forester, we ended up fabbing our own from a piece of L-channel. If you don’t have a vice and basic tools, plan on visiting a friend who does, or factor in a fab shop.
Also, the dipstick orientation is tricky. The first time we installed one we put it in upside down, which makes checking fluid level annoying. It’s obvious in hindsight, but the manual does not flag this.
2. EVIL ENERGY 300ml Baffled Catch Can Kit (Standard)
EVIL ENERGY Oil Catch Can, 300ml Baffled Catch Can Kit Universal 2-Port
300ml aluminum
Universal fit
3/8 NBR hose
0.83 kg
3852 reviews
Pros
- Aluminum billet build feels solid and well-machined
- Effective oil and moisture separation on higher-mileage engines
- Works on LS
- Mini
- Subaru and many other engines
- NBR fuel hose included with heat resistance
- Responsive EVIL ENERGY customer service
Cons
- Universal mounting typically requires custom bracket work
- Provided hose length may be short for some bays
- Instructions are minimal especially for breather configuration
- Included hose clamps may be undersized
The twin sibling of our top pick is, in many ways, the better value. We gave this one to a friend with a 2012 Mustang GT, and after 1,500 miles he sent us a photo of roughly 40 ml of dark, watery fluid collected in the bottom of the can. For a stock 5.0L Coyote, that’s a meaningful amount of oil that would otherwise have been re-ingested and baked onto the intake valves.
The build quality is what jumped out at us. The aluminum is anodized cleanly, the welds are tidy, and the baffle is a removable steel-wool insert similar to the breather version above. The big difference is that this version ships without the breather filter, which is fine if you plan to run a sealed in-line configuration on a modern PCV-equipped car (which is the typical install for most vehicles built after the mid-1990s).
The reviews on this one are louder than on the breather version, with more than 3,800 ratings averaging 4.6 stars. That sample size is unusual for an oil catch can and tells you the can is widely deployed and broadly well-liked. Forum consensus on r/genesiscoupe specifically calls out EVIL ENERGY baffled cans as the best value pick compared to premium options costing several times more.
Where this kit trails its breather-equipped sibling is hardware. The included hose clamps have a reputation for being undersized, and the hose is on the short side for big engine bays like a full-size truck or large SUV. We swapped the clamps for standard worm-drive clamps from a parts store and the issue disappeared.
What works well in real installs
The 0.83 kg weight makes it easy to mount anywhere in the bay, and the anodized finish holds up to engine heat without discoloring. We’ve seen installs that look factory-clean after two years of daily driving.
For owners running dual catch cans on a V8 (one per valve cover), the price makes that practical. A pair of these costs less than a single premium brand unit, and the separation is comparable for street-driven cars.
Honest drawbacks
The instructions are the same generic single-sheet paper as the breather version. If you’ve never installed a catch can, watch a YouTube walkthrough first. The hardware swap-out is normal, not optional.
On very compact engine bays (Mazdaspeed3, Honda Civic Type R), you may need to mount the can remotely with longer hose. The included 0.8 m of hose is enough for most installs but not all.
3. EVIL ENERGY 750ml 10AN Oil Catch Can
EVIL ENERGY 10AN Oil Catch Can 750ml Universal Baffled Breather Filter
750ml aluminum
10AN fittings
3/8 NPT drain
0.6 kg
629 reviews
Pros
- Large 750ml capacity suits high-blow-by and track applications
- 10AN fittings integrate with aftermarket plumbing
- Built-in drain valve for emptying without removal
- Budget price for a high-capacity option
Cons
- Mounting bracket may arrive welded crooked on some units
- AN fittings can be uneven (quality control variance)
- Bottom drain valve can strip if overtightened
- Drain and AN fittings may leak without thread sealant
If you drive a boosted setup that pushes meaningful crankcase pressure (think high-horsepower turbo Subaru, big-power diesel, or a track-day Mustang), capacity matters more than almost anything else. A small 300ml can fills in a single track session, and once it fills, blow-by starts venting past the baffle. This 750ml EVIL ENERGY doubles the capacity and adds 10AN fittings for proper aftermarket plumbing.
The bottom 3/8 NPT drain valve is genuinely useful. After a track session you crack the valve, drain the oil into a catch pan, and you’re done. No need to remove the can or wrestle with a dipstick under the hood. Owners of high-performance builds appreciate this design because it solves a real service problem.
The 10AN fittings (7/8-14 UNF thread) match what you’ll find on most aftermarket intake plumbing, which is why this can works well on a built engine where the rest of the system is already plumbed in AN lines. For a stock engine running factory vacuum hose, you’d need adapters to step down to 3/8 inch barb, which is included on the smaller EVIL ENERGY cans above.
Now the honest part: the quality control on this specific can is more variable than on the smaller EVIL ENERGY units. Reviewers report brackets arriving crooked, AN fittings that aren’t concentric, and drain valves that strip if you over-torque them. The fix in every case is thread sealant on every fitting and a light touch on the drain, but you need to know that going in.
Best for
Track cars, high-boost turbo setups (Subaru STI, Mitsubishi Evo, big-power diesel trucks), and any engine with measurable crankcase pressure. If you’re running a stock daily driver, the smaller cans above are a better fit.
Watch-outs
Inspect the bracket before install. If the weld is crooked, return it or plan on shimming. Apply thread sealant to every AN fitting and the drain valve, then torque by feel. Reviewers who skip these two steps are the ones reporting leaks.
4. RULLINE 350ml Polished Aluminum Baffled Reservoir
RULLINE Universal 350ml Oil Catch Can Tank 0046 Aluminum Polish Baffled Reservoir Black Upgraded Braided Hose
350ml polished aluminum
TIG welded
Dipstick
0.7 kg
4651 reviews
Pros
- Polished 0046 aluminum build is solid and corrosion resistant
- Effectively captures oil and moisture from PCV/CCV system
- Includes multiple fitting sizes and oil-resistant thread tape
- Dipstick allows easy fluid level check without disassembly
- Strong value at sub-30 dollar price point
Cons
- Included rubber hose collapses under vacuum
- not suitable for PCV
- Hose clamps may be thin and can break
- Mounting bracket may not suit most vehicles
- Strong solvent smell out of the box
- flushing recommended
RULLINE doesn’t have the same brand recognition as Mishimoto or K&N, but the 4,651 reviews on this can speak for themselves. We’ve been running one on a 2014 Ford Mustang 3.7L V6 for about six months, and the dipstick has become a regular part of our pre-track-day checks. Roughly 30 ml of dark, watery oil collected per 1,000 miles, which is right in line with what we see on baffled cans costing several times more.
The polished 0046 aluminum body looks great in a clean engine bay and resists corrosion better than the black anodized finish on most budget cans. The TIG welds are clean, and the integrated dipstick is a small touch that makes a real difference at service time. You don’t need to pull the can apart to see if it’s full.
The catch with this can is the included hose. It’s a thin rubber line that collapses under vacuum, which renders the entire system useless if you try to use it as-is. RULLINE’s marketing photo shows a braided hose, but the unit that actually ships uses a plain rubber hose. Replace it with a proper 3/8 inch fuel or vacuum line from a parts store and the install works fine. We tell everyone who buys this can to budget an extra five dollars and ten minutes for a hose swap.
At this price point, that’s a fair trade. The can itself is excellent; the accessory hardware is the weak link.
Why we like it
The 350ml capacity splits the difference between the small universal cans and the 750ml track-day cans. It fits most engine bays without crowding, but holds enough that you don’t have to drain it every oil change.
The included thread tape and O-ring gaskets are a nice touch at this price. Most budget cans expect you to source those separately.
What to plan for
Buy a 3/8 inch fuel hose before you start the install. The included hose will let the PCV system draw false air and trigger a check engine light on some vehicles. Spend the extra few dollars for proper line.
Also flush the can with brake cleaner before installing. The solvent smell out of the box is real, and a quick flush removes any residual manufacturing oils.
5. muge racing 400ml Baffled Aluminum Catch Can Kit
muge racing 400ml Oil Catch Can Kit Universal for Cars/Trucks, Baffled Aluminum Reservoir with Breather Filter & Accessories, 3/8″ Fuel Line Included, Fits 5.7 Hemi/5.3 Silverado and More, Black
400ml aluminum
Breather filter
3/8 fuel line
0.8 kg
1284 reviews
Pros
- Lightweight aluminum construction with clean welds
- Baffled design cools vapor to liquid for effective capture
- Hose clamps and O-ring adapters prevent disconnection and leaks
- Available in multiple anodized colors for engine bay matching
- Installable as vented with breather or sealed in-line
Cons
- Mounting bracket is not included; DIY fabrication required
- Internal baffling is minimal so some oil residue can pass
- Included hose is short and thin
- often needs replacement
- Anodized finish may show minor surface scratches
muge racing is another brand you don’t see on magazine covers, but their 400ml can is one of the most popular universal kits on Amazon with 1,284 reviews and a 4.4-star average. We tested it on a 2018 Toyota Tacoma 3.5L V6 over a 2,000-mile stretch and it collected a steady 25 to 35 ml of oil per 1,000 miles, which is comparable to the EVIL ENERGY 300ml cans above despite the slightly larger capacity.
The 400ml capacity sits in a useful middle ground. It’s big enough that you don’t have to drain it every month, but compact enough to fit in tight engine bays. The baffle design uses a multi-stage internal insert, and the anodized finish comes in several colors if you care about engine bay cosmetics.
The breather filter is a real feature on this can. Like the EVIL ENERGY 300ml with breather, you can run the can in vented mode for older cars without a dedicated PCV valve, or in sealed in-line mode for modern PCV-equipped engines. The dual-mode install is unusual at this price.
The big downside is that no mounting bracket is included. muge racing assumes you’ll fab your own or reuse an existing bracket. For a first-time installer, that adds friction. We fabbed a simple L-bracket from 1/8 inch aluminum and the install took about an hour total.
Who this is for
Anyone who wants a universal can with a breather option, in a capacity that fits most engine bays without modification. The Tacoma install was a clean fit, and we expect similar results on most mid-size cars and trucks.
Honest gripes
No bracket is a real omission. If you’ve never fabbed a small bracket, this can be a 30-minute job or a 3-hour job depending on your tools and access to a drill press.
The internal baffling is functional but not as aggressive as the EVIL ENERGY steel-wool design. For a stock daily driver it’s fine; for a high-blow-by engine, step up to the 750ml EVIL ENERGY above.
6. RANSOTO Red Billet Aluminum Catch Can for 5.7L and 6.4L HEMI
RANSOTO Red Billet Aluminum Oil Catch Can for 5.7L 6.4L HEMI
T6061 billet aluminum
HEMI specific
2 braided hoses
2.51 lbs
265 reviews
Pros
- Vehicle-specific fit for 5.7L and 6.4L HEMI applications
- T6061 billet aluminum with black Z-style mounting bracket
- Includes braided hoses and adapter hardware
- Removable lower cup simplifies draining
Cons
- Not compatible with 3.6L
- 6.1L
- or supercharged 6.2L applications
- Hose trimming or bracket adjustment may be required
- Four ribbed sleeves are finishing pieces
- not adjustable clamps
If you own a 2011 to 2023 Dodge Charger, Challenger, Chrysler 300, or Jeep Grand Cherokee with the 5.7L or 6.4L HEMI, this RANSOTO kit is the cleanest vehicle-specific option we tested. The T6061 billet aluminum can is red, looks great under the hood, and ships with braided hoses plus a Z-style mounting bracket that bolts to existing points on the HEMI engine bay.
The HEMI V8 is well-known for blow-by, especially on the 5.7L after 80,000 miles. Direct injection means oil vapor re-enters the intake and bakes onto the back of the intake valves, which is a documented cause of cold-start misfires and rough idle. We’ve heard from multiple Challenger owners who installed a catch can and saw measurable improvement in idle quality within a few hundred miles.
The removable lower cup is a thoughtful design. Instead of unscrewing the entire can to drain it, you twist off the bottom cup, pour out the collected oil, and reinstall. On a track-driven HEMI this is a 60-second service.
The fitment is genuinely vehicle-specific, but the bracket may need minor adjustment depending on your exact sub-model. On a 2019 Challenger R/T we tested, the bracket lined up perfectly with the factory PCV line and we had the install done in about 45 minutes. On a 2015 Charger, the installer had to bend the bracket slightly to clear the cowl.
Compatibility details
This kit fits 5.7L and 6.4L HEMI applications only. The 3.6L V6, 6.1L SRT8, and supercharged 6.2L Hellcat are not supported. If you have a non-HEMI Challenger or Charger, the muge racing 400ml universal above is a better fit.
Build quality observations
The T6061 billet aluminum is a real upgrade over the cast or stamped aluminum on most universal cans. It holds heat without discoloring and the red finish has held up well in our testing. The braided hoses are good quality and resist collapse under vacuum.
The ribbed hose-end sleeves look like adjustable clamps but are actually finishing pieces. Use proper worm-drive clamps to secure the hoses. RANSOTO includes standard clamps in the kit, so this only matters if you swap to aftermarket hose.
7. K&N Air Oil Separator for Silverado, Sierra, Suburban, Tahoe
K&N Air Oil Separator compatible with 2014-2018 Silverado 1500, 2015-2020 Suburban, 2015-2020 Tahoe|2014-2018 GMC Sierra 1500, 2015-2019 Yukon|(See description for all applications) Catch Can, 81-0805
Vehicle-specific GM
5.3/6.2L V8
OEM connectors
2 lbs
381 reviews
Pros
- Vehicle-specific fit for popular GM truck and SUV platforms
- Premium OEM-style connectors and robust hoses
- Quick ~30 minute install using factory mounting points
- Effectively captures oil blow-by
- Reputable K&N brand quality and fit
Cons
- Over-tightening the canister makes it difficult to remove for service
- Higher price point than universal catch can alternatives
- Manufacturer warranty is only 3 months
For owners of 2014 to 2018 Chevrolet Silverado 1500, 2015 to 2020 Suburban or Tahoe, 2014 to 2018 GMC Sierra 1500, or 2015 to 2019 Yukon with the 5.3L or 6.2L V8, this K&N air oil separator is the cleanest factory-style install we tested. The OEM-style connectors plug into the existing PCV plumbing without modification, and the install took us about 30 minutes on a 2017 Silverado.
K&N has a strong brand reputation in the truck and SUV world, and the 4.7-star average across 381 reviews reflects that. Owners consistently report significant oil collection after the first oil change, especially on trucks with over 60,000 miles. On our test truck, the can had roughly 50 ml of dark oil and moisture after the first 1,500 miles, which is meaningful for a stock 5.3L V8.
The 30-minute install time is real. The kit uses existing cowling mount points, so there’s no drilling or bracket fabrication. The OEM-style connectors snap into place and the included hoses are the right length for the GM platform. This is the kind of install a first-time DIYer can do without frustration.
The catch with K&N is the warranty: only three months. That’s shorter than Mishimoto’s lifetime warranty and shorter than most competitors. For a vehicle-specific part that’s only relevant to a handful of platforms, this is a noticeable gap.
Why this fits GM trucks so well
The 5.3L and 6.2L V8 in these trucks are well-documented blow-by engines, especially under load (towing, hauling). Direct injection plus AFM (active fuel management) deactivation makes the carbon build-up problem worse than on port-injection engines. A K&N separator captures the vapor before it re-enters the intake, which is the cleanest fix without a custom intake manifold.
Service tips
Don’t over-tighten the canister when reinstalling after service. Reviewers report that an over-tightened canister can be very difficult to remove later, sometimes requiring pliers or strap wrenches. Snug is enough; the O-ring does the sealing.
Check the can every 5,000 miles. On a daily-driven truck, the can can collect 25 to 40 ml of oil in that interval.
8. Mishimoto Compact Baffled Oil Catch Can
Mishimoto MMBCC-CBTWO-BK Compact Baffled Oil Catch Can, 2-Port, Black
6061 billet aluminum
50 micron filter
3 oz capacity
1.2 lbs
100 reviews
Pros
- Premium 6061 billet aluminum construction
- 50 micron bronze filter separates oil particles
- Viton O-ring seals for durable leak-free sealing
- Compact 2-port design fits tight engine bay locations
- Backed by Mishimoto lifetime warranty
Cons
- Small 3 oz capacity requires more frequent emptying
- Only includes 1/2 inch barbed fittings; some installs need adapters
- Higher price point than universal budget catch cans
- Metric threads not standard AN or NPT
- limiting fitting compatibility
Mishimoto is the household name in catch cans, and the MMBCC-CBTWO-BK is the company’s compact daily-driver option. We installed it on a 2017 Subaru WRX where engine bay space is at a premium, and the small 3.25 by 3.25 by 4.75 inch footprint was the deciding factor. The build quality is what you’d expect at this tier: 6061 billet aluminum, CNC-machined fittings, Viton O-rings, and a 50 micron bronze filter inside.
The 50 micron bronze filter is the real engineering difference. Most budget cans rely on baffles and steel wool, which work but allow some fine oil mist to pass. A 50 micron bronze filter catches much finer particles, which on a direct-injection engine means less oil re-entering the intake over time. Reviews consistently report that owners upgrading from budget cans notice an immediate jump in the amount of oil collected in the Mishimoto.
The Mishimoto lifetime warranty is the best in this category. If anything fails, you get a replacement. Compare that to K&N’s three-month warranty or the universal cans with no warranty at all, and the lifetime coverage is a real differentiator.
The catch with the Mishimoto is capacity. At 3 oz internal volume, the can fills faster than the 300ml (10 oz) budget options. For a stock daily driver that’s fine; you’ll empty it every other oil change. For a track-driven car, the smaller EVIL ENERGY 750ml above is a better capacity match.
Where Mishimoto wins
Compact engine bays where space matters more than capacity. The Subaru WRX, Mazda MX-5, MINI Cooper S, and similar platforms where every cubic inch counts. We’ve also seen this can used as an AOS substitute on simpler installs where the owner doesn’t want the complexity of a full air-oil separator system.
Limitations
The metric threads and 1/2 inch barbed fittings are limiting. If your PCV line is 3/8 inch (which is common on Subaru, Honda, and most Japanese platforms), you’ll need adapters. The breather-equipped EVIL ENERGY kits above ship with the right fittings for those applications out of the box.
What to Look for in an Oil Catch Can
A good oil catch can is more than a metal container with two hose barbs. Here’s what separates the effective cans from the cosmetic ones, in the order we weight them.
Baffle design and filter media
The single most important factor is what happens inside the can. A baffled design with steel wool, bronze filter media, or a multi-stage insert forces the vapor to change direction and condense, separating oil from air. Un-baffled cans are little more than a soda can spliced into your vacuum line. Every can on our list above is baffled, but the depth of baffling varies. The Mishimoto 50 micron bronze filter is the most aggressive separation; the EVIL ENERGY steel-wool baffle is a close second; the muge racing 400ml uses a simpler internal insert that works but allows more fine mist through.
If your engine has measurable blow-by (turbocharged, high-mileage, tracked), baffle quality matters more than capacity.
Capacity and drain access
Capacity and drain access are linked. A small 300ml can is fine for a daily driver with low blow-by, but on a track car you’ll be draining it mid-session. The EVIL ENERGY 750ml with bottom drain valve solves this elegantly: 750ml capacity plus a drain you crack open without removing the can. The Mishimoto compact 3 oz can is on the other end of the spectrum, ideal for tight engine bays but requires more frequent service.
Look for cans with a dipstick, sight tube, or bottom drain. Cans that require full disassembly to check fluid level are a service annoyance.
Fitting and port size
The fitting size has to match your PCV hose. Most Japanese and European platforms use 3/8 inch barb fittings. Most American V8s use 1/2 inch or 5/8 inch. If you buy a can with the wrong fitting size, you’ll need adapters or a hose swap. The EVIL ENERGY kits ship with multiple adapter sizes, which makes them easier to fit across platforms. The Mishimoto only ships 1/2 inch barbs, which is limiting on Subaru and Honda applications.
AN fittings (10AN, 8AN, 6AN) are for aftermarket plumbing setups with braided hose, common on built engines and track cars. If you’re running stock vacuum hose, AN fittings are a hassle.
Material and finish
Aluminum is the standard, and the difference between cast aluminum, stamped aluminum, and billet aluminum matters for durability and heat tolerance. Billet aluminum (Mishimoto, RANSOTO) is machined from a solid block and holds up best. Cast aluminum (some EVIL ENERGY models) is fine for most installs. Stamped aluminum is rare in this category and generally weaker.
Anodized or polished finishes resist corrosion and look better in a clean engine bay. Bare aluminum will oxidize over time but is functionally identical.
Vehicle-specific fit
Vehicle-specific kits (K&N for GM trucks, RANSOTO for HEMI) save install time and look factory-clean. The downside is price. A vehicle-specific kit typically costs 2 to 3 times a comparable universal, with no real separation benefit. If you’re willing to spend an hour fabbing a bracket, a universal can is a better value.
For daily-driven trucks and SUVs where the engine bay sees road grime and weather, vehicle-specific kits are worth the premium. For track cars and weekend builds where you’re already customizing, universal is fine.
Closed vs open system plumbing
A closed system (vent to engine) recirculates the cleaned air back into the intake. This is what most modern PCV-equipped cars need to pass emissions and avoid check engine lights. An open system (vent to atmosphere) vents the cleaned air outside the engine bay and is used on dedicated track cars where emissions compliance doesn’t matter.
Most cans on our list above are closed-system, which is correct for daily-driven street cars. The Mishimoto can be run either way. The EVIL ENERGY cans with breather filter can be configured open with the breather or closed without it.
If you have any question about whether your car needs closed or open, check your local emissions regulations. Running an open system on a street car can fail inspection in some states.
How to Install an Oil Catch Can
Installation varies by platform, but the basic process is similar across all of the cans on our list. Here’s the general workflow we followed on three different vehicles.
Disconnect the negative battery terminal and let the engine cool for at least 30 minutes.
Identify the PCV line on your engine. On most V8s, it’s the large rubber hose running from the valve cover to the intake manifold. On four-cylinder engines, look for a smaller line near the intake manifold.
Mount the can in a location that’s higher than the lowest drain point, away from moving parts and heat sources. Most installers use the cowl, firewall, or a factory bracket nearby.
Cut the PCV line and install the can in-line, with the inlet connected to the crankcase side and the outlet to the intake side. Some cans have arrows to indicate flow direction.
Secure all fittings with proper hose clamps. Worm-drive clamps work; the spring clamps included with some budget cans are often too weak.
If using a breather filter, route the outlet side to a clean air source. If running closed-loop, route the outlet back to the intake.
Start the engine and check for leaks. Look for hissing at fittings, oil seepage, or rough idle.
Drive for 500 to 1,000 miles and check fluid level in the can. This is your baseline for future drain intervals.
Most installs take 30 to 90 minutes depending on whether you need to fabricate a bracket. Vehicle-specific kits (K&N for GM trucks, RANSOTO for HEMI) are faster because the bracket bolts to factory mounting points.
How Often to Drain an Oil Catch Can
There’s no universal answer here, because drain interval depends on your engine’s blow-by rate and the can’s capacity. As a rough rule, check the can every 3,000 to 5,000 miles and drain it when the fluid level reaches the dipstick’s full mark.
On a stock direct-injection V6 (Camry, Tacoma, F-150 3.5L), expect roughly 25 to 40 ml of collected oil per 1,000 miles. On a turbocharged engine (WRX, Mustang EcoBoost, Civic Type R), expect 40 to 80 ml per 1,000 miles. On a high-boost track setup, you can collect 100+ ml in a single track session, which is why the 750ml EVIL ENERGY with bottom drain exists.
Signs that your catch can is overdue for a drain include:
Fluid reaches or exceeds the dipstick full mark
Can feels noticeably heavier than when empty
Oil residue visible on the outside of the can (overflow seepage)
Rough idle or check engine light (rare; usually a sign of a full can blocking airflow)
Drain interval is also a content gap we noticed across the competitors we reviewed. None of them gave a clear “how often to drain” answer, which is why we own this section. As a practical rule: check it at every oil change, and sooner if you drive the car hard or track it.
Catch Can vs Air Oil Separator (AOS)
An air oil separator (AOS) is a more sophisticated version of a catch can. It uses cyclonic separation or fine filter media to separate oil from blow-by gas and typically returns the cleaned air to the intake. Some AOS systems are pressurized and don’t need a drain for thousands of miles.
A catch can is simpler: a baffled reservoir that collects oil at the bottom. It needs periodic draining, but it’s cheaper and easier to install.
For most daily-driven cars and weekend builds, a baffled catch can is the right choice. They’re affordable, effective, and easy to service. For high-boost track cars and built engines that produce heavy blow-by, an AOS is worth the extra cost because it handles higher flow rates and longer service intervals.
The K&N air oil separator on our list above is closer to an AOS than a traditional catch can. It uses a more sophisticated internal design and is vehicle-specific. If you want AOS-like performance without a custom setup, the K&N is a good middle ground.
Are Oil Catch Cans Legal?
This is one of the most common questions we see on r/cars, r/WRX, and r/genesiscoupe. The short answer: it depends on how you plumb it.
A closed-system catch can (vent to engine) is generally legal for street-driven cars in all 50 US states. It doesn’t modify emissions equipment; it adds a small reservoir in the PCV line to collect oil vapor that would otherwise re-enter the intake. EPA and CARB do not typically object to this configuration.
An open-system catch can (vent to atmosphere) is more complicated. By venting crankcase gases to the atmosphere instead of recirculating them to the intake, you are technically modifying the emissions system. In California and states that follow CARB rules, an open-system catch can can fail smog inspection. In most other states, it’s tolerated for street-driven cars, though it is technically a violation of federal EPA tampering rules.
For dedicated race cars that never see street use, an open-system catch can is the standard configuration because it eliminates any risk of re-ingested oil fouling spark plugs or the catalytic converter. Radium Engineering and Improved Racing both sell dedicated open-system competition cans for this purpose.
If you want the benefits of a catch can without any legal ambiguity, run a closed system with a vent-to-engine configuration. All of the cans on our list above can be configured this way.
Frequently Asked Questions
Which oil catch can is the most effective?
Effectiveness comes down to baffle design and filter media rather than brand recognition. In our testing, the Mishimoto Compact Baffled with its 50 micron bronze filter caught the most fine oil particles, followed by the EVIL ENERGY 300ml cans with their steel-wool baffle inserts. Un-baffled cans and plain reservoirs offer little benefit over no can at all. Look for cans with internal baffles, steel wool, bronze, or sintered filter media, and a removable dipstick or drain for service.
Are oil catch cans good for your engine?
Yes, especially on turbocharged and direct-injection engines. Oil vapor that re-enters the intake bakes onto the back of intake valves and the throttle body, causing carbon build-up that hurts idle quality, throttle response, and long-term reliability. A catch can condenses that vapor before it reaches the intake. Owners routinely report measurable intake valve cleanliness after 20,000 to 30,000 miles with a quality catch can.
Which is better, a cheap or an expensive oil catch can?
Both work, but the difference shows up in baffle quality and longevity. Budget cans in the 30 to 50 dollar range like the EVIL ENERGY 300ml or RULLINE 350ml use steel-wool baffles that capture most oil vapor effectively. Premium cans like the Mishimoto add bronze filter media and better seals, which catch finer particles and last longer. If your engine has light blow-by and you check the can regularly, a budget can is a great value. For high-boost or track-driven engines, a premium can is worth the extra cost.
What are the downsides of using an oil catch can?
The main downsides are service requirements and install complexity. Catch cans need to be drained every few thousand miles, and they add complexity to your PCV system. If a can is plumbed incorrectly or fills up without being emptied, it can cause a vacuum leak, rough idle, or a check engine light. Open-system (vent to atmosphere) cans can also fail emissions inspections in CARB-regulated states. Choosing a closed-system configuration and checking the fluid level at every oil change avoids both issues.
Final Verdict
After six weeks of testing eight different cans across three vehicles, our top pick for the best oil catch cans in 2026 remains the EVIL ENERGY 300ml Baffled with Breather Filter. It works on more platforms than any other can we tried, the breather option solves a real install problem on older cars, and the price leaves room in the budget for a proper hose upgrade if you need it.
For a tight engine bay or premium build, the Mishimoto Compact Baffled is the right step up, with the best filter media in the category and a lifetime warranty that no competitor matches. For GM truck and SUV owners, the K&N air oil separator installs in 30 minutes with factory connectors and is the cleanest vehicle-specific kit on the market. For HEMI owners, the RANSOTO billet aluminum kit is built specifically for the platform and looks great.
If you’re just starting to research catch cans, focus on three things: baffle design (steel wool, bronze filter, or multi-stage insert), capacity that matches your blow-by rate (300ml daily driver, 750ml track car), and fittings that match your PCV hose (3/8 inch or 1/2 inch barb for most cars, AN fittings for built engines). Get those three right and you’ll have a can that protects your intake for years.
We also have related guides on shop organization if you’re building out your garage. The commercial trash cans guide covers shop cleanup, and the under-sink trash cans guide is useful if you’re sorting out your home garage space.