Does venting the BOV change mpg?

[Jeremy8302]

Will venting my BOV decrease my gas mileage? If so, how much of a drop off would I see?

 

[AWDtsi1995]

You will lose hp and im not 100% sure but you will lose mpg because your screwing up already measured air that supposed to recirculate back into the intake.

PS be careful with venting questions they dont like that around here. Unless your doing it the right way with a gm

 

[madman55]

I bought my car "vented" and just recently installed new hard pipes and a greddy rs bov recirculating, and i have noticed better mpg. I went from right around 200-220 miles before the light came on to today at 280 miles it just came on. "warning some results may not be typical"

 

[Jeremy8302]

If I do decide to vent the BOV I would be using a maf-t.

 

[xveganxcowboyx]

I doubt a ventilated system, whether done properly or not, would have a noticeable effect on mileage. Probably a fraction of a MPG for most people. (obviously it could vary with how often you are venting)

 

[1993eclipseGS]

Actually a vented bov is very bad. I've seen 60 miles to a tank already on cars with vented bovs, Filling up twice a day every day. Do not vent your blow off valve without a maf-t, Vpc, ems, etc etc...

 

[xveganxcowboyx]

How does it effect mileage that badly. I've heard people claim this, but it should only momentarily effect air fuel ratios, which could effect mileage. Is it possible it throws the ecu off and runs rich all the time?

BTW, he was talking about venting with MAFT, not just unhooking the dump tube or any other stupid idea (where mileage would be only one of many concerns)

 

[dwdsm]

Don't do it. It's not worth the louder sound. Listed to these guys they have been around DSM's a long time. Get a hard pipe kit with a greddy if you want some sound, Mine is (was, dsm down) very loud even with the recirculation tube connected.

 

[DSMxJB]

I don't understand how you'd lose mileage or HP. I mean HP wise such as a dyno run you are running wot and you bov isn't blowing off as long as it's holding the boost I don't see how you'd lose HP. I understand boost recovery would be different but HP wise venting shouldn't have anything to do with it. Gas mileage I don't see how either. I understand that you are running rich between shifts because it's putting fuel for the air that should be there but regardless of if the air is there or not it's still putting fuel, though I'm pretty drunk and probably wrong.

 

[Alan11]

Without a proper Engine management you are throwing of your Air and fuel ratio. Meaning more gas to compensate the air going in.

I suck at explaining.

 

[RogueTalonTSI]

Fuel trims. Vta increases your fuel trims thereby making the car run rich all the time not just when your bov goes woosh. Another side effect of jacked fuel trims is encountering fuel cut.

 

[JusMX141]

Fuel trims. Vta increases your fuel trims thereby making the car run rich all the time not just when your bov goes woosh. Another side effect of jacked fuel trims is encountering fuel cut.

How does venting effect the air that is metered when the valve is closed?

 

[phunny]

Hahaha nice to see it just doesnt happen to me. This thread is 5 years old.

 

[Gostlrs]

I personally think people only get worse gas mileage because they are always rev'n it up to make it vent to show off......

If you drive it normally there is no real difference. I have owned 4 DSM's & everyone was vented without any problems at all...

Its an argument that is old as hell on here & neither side is right..HAHAHA