'92 R129 500 SL, Check Engine Light and Gas Mileage

[Mike Miller]

Maybe I am loosing it, but a strange thing happened to me last weekend. I drove to San Diego and got about 17-18 mpg for the 100 mile trip at 75-80 mph. While in San Diego, my Check Engine light came on. I figured I would drive back to Huntington Beach and have my indy check it out. Sunday I filled up in SD and checked the starting mileage. At about 75 miles on the return I began to think something was wrong with my gas gauge. When I got to HB I topped off the tank, to be sure of what I saw. Low and behold I got 25 mpg coming back at a steady 75-80 mph speed!!!

I am ready to reset the light and keep driving to see if it repeats!

Have any of you experienced similar changes?? Can any one of our technical guys explain that big a jump? I appears the car was running very lean, BUT....The car ran perfectly, no hestitation or cooling issues.