3800 Series II MPG?

**PsychoGT** · 03-07-2009

Hey everyone,

I have an '03 GT 4-door and I am not getting very good mileage with it (21-24 mpg with lots of highway driving). I used to get around 25-27 mpg (or better if it was all highway miles) with an '03 Impala LS with the 3800. I bought the GP used so I don't know what the gearing is because I don't have the original paperwork. And I don't know what the gearing was on the Impala either.

I am guessing the gear ratios are different on the two cars and maybe that is why the difference in mileage? I am changing the sparks soon so maybe that will help. Also I had the K&N FIPK on the Impala and I have a Cold Air Induction CAI w/K&N on the GP. I am just curious what you guys are getting with your 3800s as far a mileage goes. Any tips on add-ons or driving styles would also be appreciated. Thanks.

PGT

**Sabrewings** · 03-07-2009

3.29 gearing on your GP GT. 3.05 Gearing on a Impala LS.

**PsychoGT** · 03-09-2009

Well, that would seem to explain it. Thanks Sabrewings.

PGT

TDCRacing · 03-09-2009

Also cold air intakes will make you suffer on the MPG end. Hot air = more MPG's ......

Also how are you keeping track of you're miles?

**PsychoGT** · 03-10-2009

Originally Posted by TDCRacing

Also how are you keeping track of you're miles?

Just dividing miles by how many gallons I fill up with at the pump.

PGT

**Coogles** · 03-12-2009

Originally Posted by TDCRacing

Also cold air intakes will make you suffer on the MPG end. Hot air = more MPG's ......

Also how are you keeping track of you're miles?

I don't know how true that is. Maybe a HAI would be better, but when I had a stock GT my very first mod was a Wizair and I noticed my overall mileage jumped up by ~1mpg across the board.

TDCRacing · 03-12-2009

Originally Posted by Coogles

I don't know how true that is. Maybe a HAI would be better, but when I had a stock GT my very first mod was a Wizair and I noticed my overall mileage jumped up by ~1mpg across the board.

Cold air is more dense with oxygen, therefore it will use more fuel to achieve the proper air/fuel ratio the computer is looking fo. Warmer air has less oxygen and will use less fuel to achieve the same ratio.

You should try switching to an open cone and see how many you pick up

**Scimmia** · 03-12-2009

But with denser air, you need less of it to make any given amount of power. Add to that less pumping loss from having a a more freely flowing intake, and a CAI should increase your fuel economy.

**02BlueGT** · 03-12-2009

Originally Posted by TDCRacing

Also cold air intakes will make you suffer on the MPG end. Hot air = more MPG's ......

True in the winter, I lost about 1.5 mpg's in the winter running my wizaired, in the summer I gained .5 MPG,(both math, not DIC readings)

If you want a hai, just remove the box for the winter, and re-install in the summer