Just wanted to pick some other brains!
My wife is gripping that the gas milage has dropped off on her 01 CLS.
Plugs were replaced within 15,000 milkes.
K+N filter is clean.
She does run 89 octaine gas a lot. I don't know if that has an effect.
I don't believe there is a replaceable fuel filter.
I put "Techron" in it a every oil change.
So....
Anything I am missing?

 

You should really put in 93 octane. I bet you gas mileage will go up.

 

Yeah, it states in the owners manual that the car should only run on premium gas. 91 or 93 octane. Anyhting less and you get engine knocking and reduced mileage. Even at high altitude I still run 91. Try it and see if you notice any difference, if not there are fuel injector cleaners that are sold at automotive stores. I run a bottle every oil change.

 

check your tires. make sure the trunk is not overloaded with lots of heavy junk. I agree definitely with the injector cleaner you will see a big improvement.

 

"make sure the trunk is not overloaded with lots of heavy junk"

The car's or the wife's?

 

trying using sports shift or drive in 5, I get almost 60 more miles to the tank.

 

What is the miles per gallon you are getting by the way? And everyone else?

I drive half city and half highway and I'm gettin right around 21 mpg so far. Thats low, what do you guys think? I just brought and put in a K&N air filter, put in the injector cleaner in the gas, and changed my ac cabin filters. Hopefully, I'll see a difference.

Also, I just brought the car used from a non- Acura dealer. Not sure if they used 5-20W engine oil.

So new plugs will help too eh? I'll do that soon.