I filled up with fuel again today with B20 and checked my mileage again. 21.8 MPG

After a quick ride with my GPS (again) I found that 10 miles traveled according to the GPS is only 8 miles on the odometer in the car! That is a massive difference. This would mean my actual fuel economy is 26MPG which is what I was expecting when I bought the car.

My first thought was that at some point someone swapped rear ends. But, I just went out and looked at it. The little tab off to the drivers side says 2:88. So, that is the right rear for a 1985. So is it possible that someone put a cluster from a car with a 3:07 in there? Or would it be more related to the transmission?

The weird thing is that the speedometer is pretty accurate. On the GPS an indicated 60 MPH is 61 on the cluster. At 70 MPH on the GPS the cluster is showing 69 MPH.

RPM's @ 60 MPH are 2,600. RPM's @ 70 MPH are 3,100.

__________________
AJ

1985 300D (SOLD)