Tune up on a 3800?

[BLACK6PACK]

The parental units have a 1999-2000 something buick 4 door (park ave?) that they say is getting worse in gas milage and think it needs a tune up. Since dad is retired and has all kinds of time, I told him to do it himself. He asked what all should be done, and I wasn't sure. Not a whole lot u can do to a modern car (no carb to tweak). I told him, plugs, wires, fuel filter, air filter, oil change, anything else? I think it has about 70-80k miles on it.

TIA.

 

[Aztlanahauc]

O2 sensor if it has not been changed in a while.

 

[klrv6]

And fresh trans filter and fluid...

What mileage is it getting? What did it used to get?

 

[BLACK6PACK]

Used to get 27-28 city and highway and now is in the 22 range. Kinda crazy a bigger car like that (not huge) with a 3800 motor and on the highway gets 30mpg+.

 

[MY T FAST]

27-28 in the city?!?!?
that is unreal! i'd say dad was miscalculating before. i have a 98 gtp and 22 is pretty good for city driving. i get 27-28 with about 85/15 highway/city driving. i'd say if you're getting 22 city the car is running fine. granted, a tune up never hurts, but i don't thing you have much to worry about.

 

[BLACK6PACK]

The 27-28 was city and highway. Probably mostly highway, not sure. Its only getting 22 mostly highway now.

 

[MY T FAST]

yeah, then a tune up is probably in order.

 

[klrv6]

Climate control?

My 03 regal can eat 2-3mpg if I have the climate control set to "Auto". The "Auto" setting can run the compressor even if it's below freezing out. If I set it to auto and change the fan speed, it drops out of auto and the compressor turns off. My regal hits 33mpg on the highway now. Not too bad for a 200hp engine that I'm just getting into tuning.

 

[HUMBLE-U2]

tires, make sure there inflated to spec on side of tire.

 

[BLACK6PACK]

They're in Naples, FL, so I don't think they're worried about running the compressor when its cold outside. :wink:

Thanks for all the input guys. I'll be checking all of this out.