'97 Lesabre 21.6 Miles Per Gallon?

[Smith1000]

I drive mostly highway to work (34 miles one way) about 60 miles per hour average. It takes about 35 minutes with stops; sometimes 40 minutes. The highway speed is about 70-75 mph. Only 2 stoplights the whole trip and a short distance in town. Recently, my mileage has been about 21.4 to 21.6 miles per gallon. It seems like it used to do better. I used to get maybe 26 miles per gallon. Last week I:

Replaced the oxygen sensor
Replaced the air filter
Replaced the PCV valve
Replaced the plugs

I checked the mileage this morning, it was 21.6. It seemed like it was running better and doing better on gas. It had about a half a tank when I tuned it up. So, this tank may be better.

What else could I do next as an effort to improve the gas mileage? The engine and transmission are working fine. What would be the next item on the list to take a look at? Thanks.

[tman]

tsk tsk tsk, People always forget about the plug wires. I can't stress it enough, whenever you replace the plugs, get new wires too.

[Smith1000]

I guess so. They look like they are in really good shape, but they are maybe 3 or 4 years old. Think that could help out the gas mileage too?

[tman]

Maybe one or 2 mpg, the date of manufacuring is usually stamped on replacement Delco/Delphi wires.

[spinne1]

Making sure your tire pressure is correct can also improve gas mileage. Also, check for engine codes in case something is out of spec and the computer is having to use a generic setting for something or other to keep it running smooth.

[Smith1000]

I'll check the tires. I think they are okay because I checked them not too long ago, but it seems like it is impossible to tell if they are low by looking at them. I may run it by Autozone and have them check the codes. I think it is doing better on this tank. Before the tune up, it was going about 178 miles when it reached 1/2 tank. Today, it was about 210 or 215 miles when on a half tank. So, it seems like it's doing better this on this tank. We'll see how fast the second half goes. Thanks.

[auto trainy]

I don't know if they change your fuel for the winter months but here in the NE we usually drop a couple of mpg in the winter do to reformulation,if they do that where you are you just might have to wait for warmer weather,if you do replace your wires only use Delco wires,this is not a sales pitch GM engines run best with Delco Parts,Good Luck

[Smith1000]

Maybe I will go ahead and pick up some Delco wires. I have replaced them before, but I don't think they are Delco.

If they reformulate the gas in NE, they will do the same in KS I imagine. They are constantly reformulating the price, that's for sure. I thought they made gas more explosive for the winter months.

It is doing better on gas this week. It's just about on 300 miles and it still has a full quarter tank left. If it would run up to 350 and just slightly into the orange before gassing up next, that would be great. Thanks.

[Smith1000]

Checked today. 340 miles on 15.049 gallons for 22.59 miles per gallon. So, I gained about 1 mile per gallon.