My NA '93 940 has 225k miles and the idle rpms were drifting. I never cleaned the throttle body, or looked at it for that matter. Last year I bought the new gasket and link ends but never got around to doing the work. You know, wait until it breaks until you fix it.

I purchased the 3M Throttle Cleaner product and did the job two weeks ago. It didn't take that long, even for a first timer. I was careful and I took my time. Make sure those vacuum line holes are clear, and use the force of the spray to make sure. One of them was filled with solid material and took some patience to clear out. The throttle body was filthy, and the crud was hard to remove.

The first few days there was a noticeable improvement but not perfect. It took about a week for it to idle perfectly, but eventually it did.

The big benefit came today. I had to make a meeting in Indianapolis from my home in Michigan. I drove a consistent 75-80 mph without AC and pulled 28 mpg. I have never experienced that kind of economy with this car.

Is this consistent with anyone else's experience? Does the throttle body condition have that much impact on fuel economy?

Cheers to all.

Mark