I just sold my 2001 Oldsmobile Intrigue and received our 1989 Chevrolet K5 Blazer as my main vehicle. I am currently getting around 9 miles per gallon in city driving. I am not a lead foot, and I am driving like a grandma to try to improve this. It isn't improving as of yet. I have put in GUMOUT fuel injector cleaner to try to clean the TBI unit, but it hasn't shown any significant improvement. The Blazer only has 36,000 miles, has a Pro-Comp high lift cam, has the 350 V8, 700 R4 transmission with overdrive, and a GM 10-bolt rear axle with posi. Is there anything I can do to improve my gas mileage?