Disappointing 94 wagon

LT1 with 106,000 mi.
2:56 rear end.
I've never achieved better than 17mpg.
I baby it on take off.
What should I do first?

When was the last time you did the standard tune-up stuff?

Plugs, wires, air filter, fuel filter etc?

LT1 with 106,000 mi.
2:56 rear end.
I've never achieved better than 17mpg.
I baby it on take off.
What should I do first?

this vehicle when driving intown stop/go etc gets about 15mpg..

on the hwy at 70mph you should get 23-25mpg...

replace the air filter every 12-15,ooomi if paper type...more often in on off pavement driving...

get CRC MAF cleaner and give the sense wires a small spray ..these MAF sensing wires dirty will effect air mixture ...


at 100,ooomi replace the upsteam O2 sensors these also adjust fuel mixture....replace the PCV and inspect all these hoses for cracks splits poor fit ALL...

Use synthetic engine oil 5-30wt ..

keep tires inflated to 35 PSI..

Rod,

I'd agree with the j cAT except that since you live in a warmer summer climate use 10W30 synthetic. Your owners manual will show the appropriate temperatures and viscosity ranges, and since synthetic doesn't play the same viscosity game as polymerized mineral oils, you can use 10W30 at much colder temperatures. Engine life will be greatly improved.

Your biggest enemy is mass and kinetics. Getting almost 6,000 pounds moving is no small chore. Once it is moving you meed to keep it moving if possible. I regularly pull down 25 MPG in my fairly modified '94 Impala w/ 3.08 gears and it doesn't get babied (once it's warmed up).

As advised, install clean OEM plugs, make sure the wires are in top condition, maintain filters. keep the MAF and throttle body clean, maintain the transmission and rear gear oil (more important than you might think - Mobil 1 again), run the tires at maximum rated pressure, repack and adjust the front wheel bearings and make sure the brake calipers are floating freely, take excess weight out of the vehicle, and don't worry as much about treating it like a Florida retiree on take-offs. BMW performed an in-depth study some years ago and determined that accelerating more quickly to the desired speed and entering cruise fuel trim sooner actually improved fuel mileage. Granted, their Bosch-derived control scheme is not quite as sophisticated as Delphi's, but similar accel enrichment occurs while you are accelerating in a GM car.

The 2.56s suck for fuel economy unless you can set the cruise somewhere above 65mph and leave it there for a prolonged period of time.

Many of us put these in drive instead of overdrive.