New Car - poor fuel economy

[98SVTC]

The wide variability in mileage everybody gets seems strange.

It's not strange at all, given all the variables. If twenty people are involved in this post, right there you've got the possibility for twenty different driving styles, levels of car maintenance, fuel quality, geographic areas, etc. All things that contribute to fuel mileage. Given the "take it to the redline" mentality of many posters, I'm surprised the fuel mileage average isn't lower.
Karl

 

[Kevinm]

Reading this tells me you are not able to isolate HWY from local driving. Even though you drive the majority of hwy driving you still are driving in town somewhat. You are recording overall gas mileage. To get HWY you eed to run a ful tank strictly on the HWY to calculate.
Lot of fuel economy issues are due to driver habits..
One other thing you may want to clean your MAF sensor with MAF claner. New plugs and wires.

 

[JimBowy]

Reading this tells me you are not able to isolate HWY from local driving. Even though you drive the majority of hwy driving you still are driving in town somewhat. You are recording overall gas mileage. To get HWY you eed to run a ful tank strictly on the HWY to calculate.
Lot of fuel economy issues are due to driver habits..
One other thing you may want to clean your MAF sensor with MAF claner. New plugs and wires.

thanks for the valuable insight. i realize part of my driving is around town but with 90% on the highway i should be doing better.

im certainly not going to drive 240 miles straight on the highway to get an idea of my true highway fuel economy - and i dont think many others will either (only when they have a purpose to do so).

its not driver habbits, im driving like grandma and still in the very low 20s

the plugs and wires are new and the air pressure is good

MAF looked okay when i was changing upper/lower intake gaskets however it might be worth cleaning anyhow

anyhow something else happened tonight - my CEL lite up and stayed on all the way home. im stopping by Autozone tomorrow to get the codes... im hoping its o2 sensors... i cant see the problem being many other things

 

[fordcupcar]

I had an O2 sensor going (not sure which one) and I unplugged my battery to clear the CEL for emissions test. Took about a week or so for my CEL to come back on. That whole time I was still getting bad mileage. (Still am, haven't had the time or motivation to get the code and buy the part).

 

[JimBowy]

scanned the code today

autozone got the code: p1151

definition - lack of o2 switches - bank 2 sensor 1
explanation - ECM could not adjust fuel trim because of lean or rich condition
probable cause:
1. fuel pressure high/low
2. MAF sensor dirty/defective
3. vacuum leak
4. leaking fuel injector or fuel pressure regulator

 

[Tony2005]

P1151, time for a new Bank 2 (radiator side) Upper O2 sensor. This is the sensor to the left of the exhaust manifold when you are looking from the front of the car. Remove the oil filter for better access (and space to turn the ratchet). You need a 22 mm (or 7/8 inch) open ended or crescent wrench (about $8). The O2 sensor removal tool costs $12 at Advance or Autozone.