My speedometer assembly was from a gas model but I recently purchased a working speedometer assembly from a member here. I verified the speed was correct with my GPS but I'm not sure I remember verifying the mileage. The gears looked intact. The top 6-digit meter is a little off from the lower trip meter. When the 10ths place rolls around, it gets to about 1-2 tenths before the top meter clicks over. I'll check it against the GPS on the ride home.

I filled up yesterday and the odometer was at just under 250 miles and I put just under 14 gallons in to top it off. I added 1.5 gallons of UMO at 1/2 tank when I changed the oil last Friday. I was just under 20MPG without considering the UMO. With considering the UMO, I am just over 16MPG. Driving conditions this last tank were harder than usual, though.

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1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge