A2BLexus

I changed my stock exhaust to the F Sport exhaust on my 2014 IS250 AWD back in November and ever since then, I've been getting significantly less fuel economy after that. I used to average around 7 mpg and now it is 8 or worst.

Noticed the fuel consumption bars go to max during start up and when I am stopped at a light / idle. Once the car is warmed up after 10 or 15 minutes of driving (Its winter here in Toronto), the fuel economy feels better.

Anyone else experience this?

Swacer

I'll be the first to say..... 7mpg? I think you have a unit conversion issue here because the only way you get 7mpg is you either drive no distance to work, or you have a V12 engine lol

Also, you say it got worse, but "increased" from 7 to 8mpg hahaha

To go from L/km to mpg, go here:

http://calculator-converter.com/l_10...per_100_km.php

Ok, joking aside, and axle back exhaust isn't going to do anything to your gas mileage. Ever.

You installed it in November, do you know what else happens in November? Cold weather. Do you know what happens in cold weather? mileage drop.

You're drawing silly conclusions, drive your car.

A2BLexus

I guess cold weather could be it. I hope so. I do enjoy the new exhaust. I used to get 11 litre per km (no more silly conversion) and now its high 13s. I've had drops in efficiency in my old car but not 20% worst. Driving happen hasn't changed. I guess I'll keep an eye out but I am curious if anyone else has experience this.

dnasians

iTrader: (4)

a cat-back exhaust will not have any significant affect on fuel consumption. any change is negligible, and if you're seeing drastic changes.... probably not the exhaust

HanaleiISF

I have not noticed any change in MPG since my F Sport Exhaust install.

paul29

No idea how or what you are doing with your conversion. The metric method is calculated to be litres per 100kms ie less is better. 11 litre per km > maybe a 3 unit locomotive consist.

pillbox

Fuel consumption is based on fuel used per distance traveled. If you are not moving, you can idle all of your fuel away without a single kilometer traveled, thus the full fuel consumption bar.

Slplknight

My car needs after install more. Because i drove like crazy.....and still after 6 month i dont come under 10l (in town)
During winter 0,5-0,7l more. Right now it's 11,7-12,3l and with a full filling the range is about 520km

Sango

iTrader: (10)

Could you tell us the numbers in L / 100 km?

Also, if you are doing the conversion to MPG, make sure you the right one and specify which MPG (US MPG / Imperial MPG), otherwise it will confuse members.

It could also be the fact that the gas stations are still using winter gas, therefore your gas would burn faster. Wait until they switch back to their summer blend, you will notice the difference.

specONE

iTrader: (3)

i think what may be happening is you are stepping on gas harder to heard the sound but drawback to this is you using more gas. lol
Could be though.

Toh

Do you mind if I ask how much f sport exhausts are? (Including tax/labor and part) I'm in thinking of getting one and the intake.

Slplknight

I am from Germany and wie use the metric system. Just like my fellow Canadians

Swacer

You do realize you could install this in like 1 hr, right?

"winter gas" does not burn faster, the cold air is more dense, which requires more fuel to keep your A:F ratio constant.

A2BLexus

Sorry for the conversion issues. I will just reference it based on liters.

LOL I wish that was the case. The car just needs a slightly heavier foot to get going now but by no means and I flooring it.


Based on my current tank of gas, I will get about 460 km. Current L per 100 km is 13.7. I don't idle my car at all.

The fuel economy is especially bad when my car has been sitting for a while. For the first 5 mins, the fuel consumption bars are maxed no matter what speed I am driving at (usually around 50 kph since I am getting out of a residential area) .

The fuel economy gets better once the car is fully warmed up which wasn't the case prior to the exhaust install.

Swacer

Honestly, just drive your car. Everything you have said is just silly.

My fuel economy has been bad when the car has been sitting for a while. Well no ******, its burning gas and not moving.

When you start, the car starts in open loop because its not warm, so yes, its inefficient. Of course the gas mileage gets better as the car gets warm, tis in closed loop tuning and at its most efficient point. This happens to EVERY car.

This is normal, the car is fine, I beg you to stop and just drive the car.

Does anyone have that meme that shows, "I got my tires changed, now my heat doesn't work" for people who connect things that don't make sense?