poor fuel economy

1991 olds 98, 3.8 vin L v6, 249,000km car consistently gets crap gas mileage, i tried altering driving habits and just squeaked out 17mpg (13l/100km) in mixed mostly city driving. Does
anyone know of any problem areas on this engine that would contribute to this? I have done plugs/wires/o2 sensor/air filter and cleaned MAF sensor elements, catalytic converter is new. Transmission is rebuilt and torque converter is a few months old. At one point someone recommended hooking up a diagnostic computer to it and reading fuel trim values but I do not have this expensive equipment. It is kind of depressing when my friend's v8 grand marquis blows my car away on gas mileage with a bigger v8 engine.
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I have essentially that same engine it two present cars, one past car. For mostly city driving, 17 to `9 is about right. Highway I can get 28 -29, but my average is about 23. How much of your city driving is stop and go rush hour? I can get 30 mpg highway and just a couple of miles of city brings me down to less than 22
I wonder how accurate your friend is and how much city driving he does. People tend to embellish the figures.
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I own a 95 Olds 88 royale with the 3.8 V6 and get on average 20-22 mpg. I don't do a lot of highway miles, mostly city. Your car sounds like it's just fine. Your buddy with the V8 is full of it! That grand marquis probably gets 15mpg with the 5.0 V8.
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CGBear wrote in alt.autos.gm

Only if he spends a lot of time on the highway. Otherwise, I would expect quite a bit less with that big engine. I have the 3.8 vin c and get 17 with a lot of in town driving. Strictly highway gets me over 30.
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wrote:

LS1 V8, stated 18/28 I actually see 16/26. The LS1 is 5.7L. V8s can get decent mileage.
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Most V8s will, if you live in hilly country. V8s produce more torque, at a higher RPM, that allows the tranny to stay in the more fuel efficient higher gears more of the time. I average 23 with my 2005 Mustang GT V8 convertible, with a 5 speed automatic, and only 22 with my 2006 V6 Lincoln Zephyr with a 6 speed automatic, where I drive around my place in the mountains of eastern Pennsylvania. When I run them around my place in Delaware, where it is flat, the Lincoln will run at 26 MPG
mike hunt

<snip>
. It is kind of depressing when my friend's v8

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and
We just got back from a combined highway, Houston driving, and more highway trip. Used 16.2 gallons for 390 miles overall. This one is however a Series II. I get very similar in the Series I, however.
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