W123

Up the tire size 1983 300D Turbo Diesel

My stock tire size is 195/70 14 ~ 24.75 inch diameter. I was considering moving up to 205/75 14 ~ 26.1 inch diameter or 215/70 14 ~ 25.9. This would, in essence, give me the effect of an overall higher read end ratio. It feels as if the engine is revving more than it should at 65 - 70mph. Is this advisable? Also, what should the expected mile-per-gallon be for this year/model assuming everything is running correctly, and a conservative driving style? Thx, Bill

Chassis Model Number

Forums

83 300D Low MPG

MPG

Finally got a chance to make an extended highway trip on my new (for me) '83 300D. This is a one-owner car with a verified 116k miles. Drove 323 miles on I-75 on cruise control for 80% of the time at 2800 rpm for an indicated 65 mph. I drove about 30 miles on city streets and the rest on cruise control at 3,000 rpm. My mpg was 24.33. The mpg seems low. EPA says 30. I wonder if new injectors are called for? Or should I look elsewhere?
Oliver

Chassis Model Number

Forums

Pages