[s-cars] Fuel Economy Problem / Question

[mlp5]

- Bad MFTS - the car's seem to be very sensitive to operating
temperatures affecting mileage.  Too cold = bad mileage, can be worth 3+
mpg gain/loss.
- Tires:  these can be good for anything up to +/- 3 mpg, maybe even
more depending on (a) construction; (b) weight &/or (c) inflation.
- old, worn tired fuel injectors (say anything going past the 150K mark
ought to be checked?)
- oil weight:  I'm pretty convinced a switch from a "standard" 10W-30 or
40 to synthetic redline 5w-30 and Mobile was worth @ 1mpg gain
- compression ratio
- Winter vs. summer gas.  In Denver, the change over from winter's
oxygenated fuel to summers "real" stuff always seems to be worth @ +2mpg
or so.
- Oh, and finally your ECU chips can make a huge difference.  

I seem to be getting a pretty consistent 390 to 410 miles per tank, on
fillups running @ 17 to 18 gallons ~> @ 22 mpg to 24 mpg combined
city/highway.  There was however a period, some time ago when the car
would reliably turn +29 mpg on long highway trips running well inflated
15" OEM wheels and "high mileage" Michelin tires, that would be @ 510 to
525 miles a tank.  Since the change over to 17" rims and associated
rubber, I've never come close to that again.

mike


>-----Original Message-----
>From: s-car On Behalf Of Rich Letsinger

>Along these lines, you mentioned getting 20mpg before
>hand and someone else said they get 350+ miles/tank in
>the city. I get 300 miles to a tank in mixed driving
>which ends up at around 17mpg. I'm really not happy
>with this even before the $2.40/gallon prices. My old
>A4 1.8T got 25mpg with a big turbo and huge injectors.
>I've changed both the MAF and O2 sensor. What else
>could drag on economy?
>
>Thanks,
>Rich