I Think Installing the Catch Can Broke Something!

[PuddleJumper]

The U.S. Environmental Protection Agency (EPA) defines April to June as the “transition season” for fuel production. Refineries lead this transition and switch over to summer-blend production in March and April.

Gasoline blends used in the summer months are different than the blends used in the winter. In the winter, fuels have a higher Reid vapor pressure, meaning they evaporate more easily and allow cars to start in colder weather. In the warm summer months, these evaporative attributes would lead to increased emissions and the formation of smog.

However, because of various state or regional requirements, 14 different fuel specifications are required for the summer months. Refineries must produce enough fuel for each area to ensure there are no supply shortages, and that can complicate the production and distribution of fuels.

Summer-blend fuel is also more expensive to make than winter-blend fuel. First, the production process takes longer and, second, the overall yield of gasoline per barrel of oil is lower. These complexities add as much as 15 cents per gallon to the cost to produce these higher-grade fuels.

May-June: Deadlines for Terminals and Retailers
The May 1 compliance deadline for terminals to fully purge their systems of winter-blend fuels is considered one of the biggest factors in seasonal price increases.

Cool! learned something new today! Thanks for the knowledge man!

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[Moe-Jave]

I swear my MPG has gone up 1.5 or 2 since I installed the thing.
I was running errands this morning and made several aggressive full throttle two lane passes.
When I got back in town I had the thought that I likely killed my good average I had going on this last fill up, so I toggled in and was very pleasantly surprised.
AFAIK, we're still on winter blend here too.

Thank you for this post. I was on the fence and just bought one. I didn't think it was "necessary" on an NA gas engine without DI...

J&L should be a sponsor and offer group deals! I like the OEM-style fittings and don't mind paying a small premium to get it.

Anyhow, I had similar feelings as you have shared here for past installations. When I installed it on my F150 3.5EB, I felt it was more of a necessity (even though it has port injection to help the DI issue). The installation on an old Tacoma didn't have nearly as dramatic results (as measured by output in the collection can).

You may have a lot of water vapor in the can, but it is clearly working as intended. I did not go with the 3oz extension (yet?). I'll install mine and report back too...

 

[Moe-Jave]

Thank you for this post. I was on the fence and just bought one. I didn't think it was "necessary" on an NA gas engine without DI...

J&L should be a sponsor and offer group deals! I like the OEM-style fittings and don't mind paying a small premium to get it.

Anyhow, I had similar feelings as you have shared here for past installations. When I installed it on my F150 3.5EB, I felt it was more of a necessity (even though it has port injection to help the DI issue). The installation on an old Tacoma didn't have nearly as dramatic results (as measured by output in the collection can).

You may have a lot of water vapor in the can, but it is clearly working as intended. I did not go with the 3oz extension (yet?). I'll install mine and report back too...

I've had my oil J&L oil separator installed for about a week...

It seems my fuel efficiency has consistently gone up over similar driving conditions. My Mojave is on 35s and it has been a while since I've seen 19MPG as my running average (probably closer to 17.5 MPG under the same conditions). Now I'm at 19 or just over...

On my F150 (also a J&L unit) I felt it had less occasions for rough combustion and saw a slight bump in fuel economy. It isn't crazy to think this could help fuel economy, and even a small change is worthwhile here. Still, pushing nearly 10% isn't trivial. Think of all the changes Jeep and other OEMs do for even 1s of percent change to improved fuel economy. Maybe something that needs even basic maintenance is too much for the general public? I've only ever seen one OEM offering, and that was Ford Performance Parts...

I am curious what other experiences here are. I'll keep an eye on this to see if this is a consistent improvement. I don't see any downsides with this catch can on our gas engines.

 

[Lunentucker]

I was doing some other work and decided to check the can with another 1000 miles on it.
No chocolate milk this time, so I'm assuming that's a condensed water vapor when the ambient temperatures are colder.

 

[Moe-Jave]

I was doing some other work and decided to check the can with another 1000 miles on it.
No chocolate milk this time, so I'm assuming that's a condensed water vapor when the ambient temperatures are colder.

I agree, and more water vapor seems consistent with colder temperature operation (saw similar comments in other forums too).

No chocolate milk here in SE AZ!

My fuel economy improvement is holding steady here...

 

[legacy_etu]

I was doing some other work and decided to check the can with another 1000 miles on it.
No chocolate milk this time, so I'm assuming that's a condensed water vapor when the ambient temperatures are colder.

Nice. Hmmm, that's a fair amount of oil you're keeping out of the intake. Dang, another thing to spend money on. Didn't figure the benefit would be there on a NA engine.

Seems like Stellantis would be installing these from the factory if a simple $150 part could help them increase mileage of their fleet by 10%.

 

[Moe-Jave]

Nice. Hmmm, that's a fair amount of oil you're keeping out of the intake. Dang, another thing to spend money on. Didn't figure the benefit would be there on a NA engine.

Seems like Stellantis would be installing these from the factory if a simple $150 part could help them increase mileage of their fleet by 10%.

I think the idea of "tampering" with emissions is enough to keep the OEMs away from that draw. As mentioned earlier, I have only ever seen a single OEM offer a catch can (Ford Performance Parts). In that example, it comes with the expected off-road-use-only type warnings.

Consider too, that such systems are not "Calfornia-legal". By implication, that means other states that adopt similar laws -- say Oregon or even New York, might also see such changes the same way. Again, this has little do with reality if maintained properly. Speaking of which, I will say that I just don't think most people can be bothered to empty a catch can! I live in one of the least populated counties in the continental US, and we don't have any emission laws of any kind...

If you never empty the can, you may have problems. So emissions and extra maintenance means it is a non-starter. Too bad. It is interesting how different engines behave in this regard. The logic is sound, however. Keeping un-measured and unexpected oil vapor out of the intake is just a win. Even without the fuel efficiency gains, I think you have smoother and more consistent combustion.

It is hard to say exactly what my fuel efficiency gains are but it is definitely improved. My own experience is that it is more than 5% and approaching 10%.

 

[legacy_etu]

I think the idea of "tampering" with emissions is enough to keep the OEMs away from that draw. As mentioned earlier, I have only ever seen a single OEM offer a catch can (Ford Performance Parts). In that example, it comes with the expected off-road-use-only type warnings.

Consider too, that such systems are not "Calfornia-legal". By implication, that means other states that adopt similar laws -- say Oregon or even New York, might also see such changes the same way. Again, this has little do with reality if maintained properly. Speaking of which, I will say that I just don't think most people can be bothered to empty a catch can! I live in one of the most sparsely populated counties in the continental US, and we don't have any emission laws of any kind...

If you never empty the can, you may have problems. So emissions and extra maintenance means it is a non-starter. Too bad. It is interesting how different engines behave in this regard. The logic is sound, however. Keeping un-measured and unexpected oil vapor out of the intake is just a win. Even without the fuel efficiency gains, I think you have smoother and more consistent combustion.

It is hard to say exactly what my fuel efficiency gains are but it is definitely improved. My own experience is that it is more than 5% and approaching 10%.

Yeah, thanks. I had a brain fart and forgot about emissions and CARB regs. Although I would "think" the exhaust would be cleaner if you're not trying to re-burn blowby but what do I know.

I hear you on the extra maintenance probably being also a reason this isn't contemplated as well. It seems that no-one takes care of their stuff anymore despite how expensive it is all getting. Hell, I swear every-time I get in my wife's car the maintenance required light is on (just an oil change). Then I ask her how long has this been on and get a sheepish grin in return.

 

[Moe-Jave]

Yeah, thanks. I had a brain fart and forgot about emissions and CARB regs. Although I would "think" the exhaust would be cleaner if you're not trying to re-burn blowby but what do I know.

I hear you on the extra maintenance probably being also a reason this isn't contemplated as well. It seems that no-one takes care of their stuff anymore despite how expensive it is all getting. Hell, I swear every-time I get in my wife's car the maintenance required light is on (just an oil change). Then I ask her how long has this been on and get a sheepish grin in return.

Right, and as enthusiasts -- we don't necessarily think emissions first! I had the same thought progression here as you!

Anyhow, for cars, think about how much "stuff" was simply dumped to the ground/atmosphere before tighter emissions. Roads were more slick on first rain, and it probably is a good change overall (memories of Texas roads in the 80s come to mind!).

Until recently, street bikes simply dumped to the road too. Today, even motorcycles are pretty tightly regulated. I have a couple dual-sport bikes that are never used on the street...and it is surprising how much emissions stuff they have now!

 

[legacy_etu]

Right, and as enthusiasts -- we don't necessarily think emissions first! I had the same thought progression here as you!

Anyhow, for cars, think about how much "stuff" was simply dumped to the ground/atmosphere before tighter emissions. Roads were more slick on first rain, and it probably is a good change overall (memories of Texas roads in the 80s come to mind!).

Until recently, street bikes simply dumped to the road too. Today, even motorcycles are pretty tightly regulated. I have a couple dual-sport bikes that are never used on the street...and it is surprising how much emissions stuff they have now!

Oh I get bikes. Don't get me started on bikes and how the EPA is screwing them up!! My son just bought his first dirt bike, a brand new Kawasaki. The thing was a total bitch to start cold. I brought it back to the dealer after diagnosing. Hell, the manufacturer "foolproofed" the air/fuel mixture screw so you can't adjust it. The manufacturer had it set so lean from the factory that she couldn't even start cold. Dealer said they do this on the carb. bikes due to emissions regs now. I had the dealer upsize the pilot jet one size so it could get more fuel. Runs good now but geesh. What a joke. Glad I bought my bike with fuel injection!

 

[OHJeeper]

My truck has never seen 15mpg. Ever! I am on 37" with 5.13 gears.

Interesting... I am also on 37's with 5.13's. My current average is 16.8 and most of that tank was highway miles in TN/KY hills on my way back from Windrock at 75 MPH on cruise.

 

[OHJeeper]

I was doing some other work and decided to check the can with another 1000 miles on it.
No chocolate milk this time, so I'm assuming that's a condensed water vapor when the ambient temperatures are colder.

I had the same experience. Here's mine from a week or so ago (warmer weather)

 

[dayusmc]

Who makes the best catch can?

 

[Moe-Jave]

Who makes the best catch can?

Is there a best? What makes me like J&L is OEM+ quality tubing (better than OEM in our case) and fittings...plus I buy American in the rare instances I can.

Really even the cheapest Amazon ones are fine. I bought one and installed it on my friend's Tacoma for $35 and it works just fine too!

 

[ShadowsPapa]

Nice. Hmmm, that's a fair amount of oil you're keeping out of the intake. Dang, another thing to spend money on. Didn't figure the benefit would be there on a NA engine.

Seems like Stellantis would be installing these from the factory if a simple $150 part could help them increase mileage of their fleet by 10%.

It's going to vary a lot with engine condition, use, driving habits and so on. Some will see almost nothing, others will see more.
There's also a later version of the PCV which might be of some benefit to some.
You aren't going to see that type of mpg increase from a catch can alone unless you have issues with the PCV system or engine condition. That just isn't going to change it any 10%
Weather changes - air humidity, air temperatures, tire and lube temperatures, all of those things contribute to better mpg once warmer weather arrives. Cold tires don't roll as well, cold lube, more fuel used on a cooler engine when starting it and the first few minutes. It's partly the gas formulation in the spring, and partly the fact that it's simply spring.
I can see a marked difference in my 4.0 equipped car once spring and cool very humid air comes in. It's the air itself helping. Humid air about 50 degrees it really shines.
I also see it at the race track on Friday evenings when the really humid night air moves in - times change on those time slips.

The problem with factory installations is - someone has to empty the dumb thing now and then and most Jeep owners aren't going to be doing that. Most don't even change their own oil, let alone check it. So a factory install by default is a horrible idea. As an option, it might work because you order it specifically and will be willing to keep check on it.
From the Jeeps and Ram trucks I see lined up waiting for their oil changes and tire rotations when I go into a dealership here, believe me, most Jeep owners aren't going to mess with it.

I know mine isn't consuming much via the PCV because in over 5,000 miles, the oil level has hardly dropped at all on the stick. Watching the oil level will tell you if there's an oil consumption problem. Mine doesn't have a problem in that way.

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