[1sicke92]

I was wondering if catless downpipes decrease the miles per gallon you get? I have AR catless downpipes if that matters. I currently get 16.3 mpg (as shown on my dash). Is this bad gas mileage for our cars?

[DR_E92]

depends on your driving habits. I tend to waste more gas but then again, now that I am running the car stock I never go WOT anymore.

[mave198]

Im at 18.2 with AR catless dps.

I think most people who mod their car think the mods reduce mpg, when really its their foot that gets heavier.

[1sicke92]

But do catless downpipes themselves reduce gas mileage, driving habits aside. I'm talking about the mod itself!

[tibra1]

Sounds about right..more power = more fuel consumption..is this an actual concern of yours?..i could care less about mpg..its all about power!..

[TOPEC]

Originally Posted by mave198

Im at 18.2 with AR catless dps.

I think most people who mod their car think the mods reduce mpg, when really its their foot that gets heavier.

this is true, because technically, with catless downpipes, there is less restriction thus the engine works less to achieve the same level of performance.

[1sicke92]

hmm...i wonder if anyone has a definitive answer. because even though the engine does work less, then that means you are running richer which means more flow, resulting in more gas? that's just my guess. but where the mechanics at on e90post???? lol...

[Brey335i]

I still average 21 mpg (about a 50/50 split between highway and city) with AR Catless Downpipes and Vanguard Exhaust. Numbers verified as late as 2 hours ago.

[335i101]

I am inclined to think.....The car breathes easier, and would get better mileage.

Isn't the cat just for emissions?? That's my thought, but I am no expert.

[R1000K3]

As other have stated, the foot becomes a lot heavier with a tune...

[vasillalov]

I still get 32-34 mpg on the highway. So it is entirely your driving style.

[Haus_07]

I'd have to agree with the driving style comments. Although, IMO the N54's do take quite some time to fully break in. I really didn't start seeing my best MPG until around 45k. My car has all the bolt-ons, and I'm running the catless raceland DP's with a custom SS exhaust which is also catless. Car now has 75k, and runs better now than it ever has. Just made a trip from Phx. AZ to San Jose CA. over the holiday weekend, and I averaged 29.4mpg doing 90+ most of the way with my DJ buddy in the passenger seat, and the car loaded down with DJ gear (she was riding low for sure!!) Not sure how many miles you have on your car, but it can make a difference.

[MKE_M3]

catless downpipes would either help, or not change mpg's at all (probably help) given identical conditions/acceleration. if you have a tune, you dash mpg's may not be accurate as sometimes the actual usage varies from what the car thinks. The only real way to gauge mpg's is over long periods of time averaging miles per gallon at each fill up.

[cwn23]

It might be the fact that you are modulating the throttle a little different because of the increase in noise and tendency to go faster since the car is easier to go

[eDDuBB]

It would depend upon your driving habits. The DPs themselves improve pumping efficiencies which improve engine efficiency which given the same operating characteristics would improve milage. So ultimately, it depends on how the vehicle is driven.

DuBB

[my nuts on your face]

Originally Posted by eDDuBB

It would depend upon your driving habits. The DPs themselves improve pumping efficiencies which improve engine efficiency which given the same operating characteristics would improve milage. So ultimately, it depends on how the vehicle is driven.

DuBB

This!

You make more power with catless dp's, BUT when you're at low throttle percentages (ie. cruising) you're not making any power anyway. So, at cruising they'll add mpg for sure. At WOT...they'll probably decrease fuel consumption or not effect it, as you'll be producing more power which requires more fuel. UNLESS, they increase efficiency enough to overcome the need for fuel to make the extra power.

[CarleeSWE]

My car has never gone below 19mpg not even at the airfield trackdays (160mph 15-20times). And I have gone from bone stock to FBO no meth and the consumption has alway been the same. I think it's really impressive for a car with steptronic and ~ 380whp

[cstmx_ryder]

Given the same driving conditions/habits, modded or not, the mpg should be the same if not better.....not to mention that most of the time when on the freeway, we're driving under vacuum, not boost.

But if you're boosting more than usual, then it's obvious that the mpg would go down. More boost=more power=more fuel consumption=less mpg....

[tibra1]

Originally Posted by Danny@****************

I am FBO, AR Catless Dp and AE Exhaust, I get about 17 mpg

+1 and I get closer to 15..

[jokergerm]

I get about 24 mpg with a heavy foot. I don't think I could get 16 mpg if I tried

[Randomaccess335]

I get better mpg when I'm hungover..... Maybe you should drink more

[secretsquirrel]

I've noticed no change after getting dps.