IW STi Forum banner

1 - 20 of 26 Posts

·
Registered
Joined
·
542 Posts
Discussion Starter #1
A few weeks ago, I purchased a BLITZ BOV for my lil STI. It sounds good but at the same time, I noticed my gas mileage going down.

I haven't been driving aggressive nor racing with my new mod on. I was commuting most the time to work, but at the same time, my last 3 or 4 full tanks of gas have had an average of 220 mi to 250 miles per tank. Before, the BOV, I was getting between 270 to 300 miles per tank.

Is there more gas consumption using a BOV on the STI? If so, my BOV is coming off.... Does anyone know anything about this situation??? Thanks.

:(
 

·
Registered
Joined
·
392 Posts
The enhanced BOV allows the turbo to release more pressure whilst the power is off, which means the turbo can spool faster when you re-apply power as it doesn't need to overcome as much negative pressure.

If the turbo is spooling faster at this point, this equates to higher boost faster and therefore higher fuel usage.

Also, I had a Blitz BOV in my old 350HP Nissan 200SX (boy could that drift ;), and it replaced some of the piping between the turbo and intercooler. Not sure if this is the case with the STI Blitz BOV, but the piping may also have some effect (on my 200SX, the BOV piping introduced a lot of exhaust popping).
 

·
Premium Member
Joined
·
2,802 Posts
Anonymous said:
The enhanced BOV allows the turbo to release more pressure whilst the power is off, which means the turbo can spool faster when you re-apply power as it doesn't need to overcome as much negative pressure.
:-?

I don't know about this. Where did you hear that from? On a stock STi I don't think an aftermarket BOV is going to do any better than the stock BOV.
 

·
Registered
Joined
·
2,773 Posts
Uh...yeah....what's a BOV doing opening when power is off? All BOV are are expensive spring valves......if there is no pressure, it isn't going to be opening.
 

·
Registered
Joined
·
347 Posts
Vader2k said:
A few weeks ago, I purchased a BLITZ BOV for my lil STI. It sounds good but at the same time, I noticed my gas mileage going down.

I haven't been driving aggressive nor racing with my new mod on. I was commuting most the time to work, but at the same time, my last 3 or 4 full tanks of gas have had an average of 220 mi to 250 miles per tank. Before, the BOV, I was getting between 270 to 300 miles per tank.

Is there more gas consumption using a BOV on the STI? If so, my BOV is coming off.... Does anyone know anything about this situation??? Thanks.

:(
A BOV releasing excess pressure to the atmosphere (rather than back to the post MAF pre-turbo intake like the stock blow-back valve) will result in worse fuel-to-air ratio. Too much fuel means incomplete combustion means lower power. Less power and more fuel means that driving the same way requires much more gas.
 

·
Registered
Joined
·
542 Posts
Discussion Starter #7
A BOV releasing excess pressure to the atmosphere (rather than back to the post MAF pre-turbo intake like the stock blow-back valve) will result in worse fuel-to-air ratio. Too much fuel means incomplete combustion means lower power. Less power and more fuel means that driving the same way requires much more gas.
.... hmm... yeah, I've heard of this explanation from different people, plus it makes sense. Also, I have now removed my BOV, and I'm now hoping to get back to usually gas consumption from my STI.

Till gas prices go down, the BOV will stay off.... cuz gas prices are just to high. Paying $28 bucks for 200 miles of gas is a little to step at this point. Thanks again everybody for your response.
 

·
Registered
Joined
·
2,773 Posts
I wouldn't do it for the price of the gas you are wasting....I'd do it more for the fact you are causing your engine to run improperly. :roll:

But good decision regardless.....
 

·
Registered
Joined
·
302 Posts
Maybe I drive too fast or maybe it's just that I have more opportunity to do it where I live.. but there is no way in hell I'll -ever- get over 240 miles to a tank with my (bone stock) STi. I think my best mileage so far (miles until the fuel light came on) is 230. My average seems to be around 220. It seems most others who post on this forum have WAY more self control than I. :)
 

·
Registered
Joined
·
392 Posts
I wouldn't do it for the price of the gas you are wasting....I'd do it more for the fact you are causing your engine to run improperly.
... Your right Rob. :) Thanks.

Also, WRXTC & guest...
YOU guys/gals only get between 180 to 220 miles on average???!!! Damm, that is weird cuz I travel to different work sights for my job, and I keep a consistent tab on my miles because I get paid for them :)

Either way, I thought that I was doing bad on my gas mileage but you guys/gals are doing worst w/ your STI's.... Ouch.... I wonder what gives because I am known to also speed around & blast off from a light once in awhile... :) So I know that I reduce my gas tank quicker but still, to only get 180 miles per tank is hard to swallow. Ouch.
 

·
Registered
Joined
·
542 Posts
Discussion Starter #12
I wouldn't do it for the price of the gas you are wasting....I'd do it more for the fact you are causing your engine to run improperly.
... Your right Rob. :) Thanks.

Also, WRXTC & guest...
YOU guys/gals only get between 180 to 220 miles on average???!!! Damm, that is weird cuz I travel to different work sights for my job, and I keep a consistent tab on my miles because I get paid for them :)

Either way, I thought that I was doing bad on my gas mileage but you guys/gals are doing worst w/ your STI's.... Ouch.... I wonder what gives because I am known to also speed around & blast off from a light once in awhile... :) So I know that I reduce my gas tank quicker but still, to only get 180 miles per tank is hard to swallow. Ouch.
 

·
Premium Member
Joined
·
922 Posts
I am hitting around 250 miles(+/- depending on how much fun I have). I know that is nothing to brag about, but this is a high performance car.
 

·
Registered
Joined
·
2,773 Posts
Damn...you guys are doing just fine on mileage. Without topping off the tank (just stopping when it clicks off), I usually only get 220 or so in town.
 

·
Premium Member
Joined
·
2,802 Posts
Same here. I am averaging about 220 a tank. Just noticed today that just about every gas station around me now has premium at about $1.99 a gallon. :roll: Gald I heard about this yesterday and filled up for $1.86 which is still ridiculous.
 

·
Registered
Joined
·
541 Posts
Almost....but not quite

MKIVSupra said:
Same here. I am averaging about 220 a tank. Just noticed today that just about every gas station around me now has premium at about $1.99 a gallon. :roll: Gald I heard about this yesterday and filled up for $1.86 which is still ridiculous.
Whoa. Count your blessings, guys. I saw a station today at $2.30 for 87 octane, $2.50 for "premium" 91 octane. And I'm sure it's worse in Northern Cal.
 

·
Registered
Joined
·
542 Posts
Discussion Starter #17
Ever since I removed my BOV, my gas mileage on my last 2 tanks of gas has gone up.

260 mi for the first tank, and 308 mi for my second tank since I removed the BOV. :)

And I am still driving the same as before.
 

·
Registered
Joined
·
2,773 Posts
Good lord man.....you either drive like my grandma....or your car sucks a lot less gas than mine!

What's your MPG looking like? Maybe you are filling up a little further than I do. I'm usually hovering right around 20 MPG.
 

·
Premium Member
Joined
·
2,802 Posts
I let my tank run a little low Sunday driving out to a "cheap" Mobil gas station I drove by late Sat night, anyway I got 245 cityish miles out of that tank. I am curious to see if switching over to synthetic makes a difference in mpg. I am driving up to Michigan to visit family for Labor Day weekend and since I will roll over 6k miles during the 280+ mile drive up there, I am doing an oil change with Amsoil while I am there. It will be a good comparo, regular oil on the way up there, Amsoil synthetic on the way back. I will post if I notice a difference.
 

·
Registered
Joined
·
983 Posts
me too, no more than 240 and the fuel light comes on why so low????????? :x
 
1 - 20 of 26 Posts
Top