Prior to replacing the two worn gears in my odometer, the trip odometer would only register about 220 miles per tank of gas, and would sometimes fail to advance at all while driving. After the replacement, I'm now getting over 300 miles per tank! After double checking for correct tooth numbers in the gears, I am confident the Volvo is (and probably always was) getting great mileage.

kourt
87 245
Austin, TX

Yeah a bad odometer can really spoil your mileage, I've put about a thousand bucks worth of fuel into the brick's tank, and failed to go anywhere according to the speedo.
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Drive it like you hate it

It's always nice when things work.

I've been driving '86 & '89 245's with auto trans. Never got 300 mi./tank unless driving the gas gauge way down into the red zone. If that's what you're doing, tank up sooner and possibly avoid ruining your main fuel pump.

Another likely cause of false high miles on the speedometer/odometer is wrong (smaller) tire size. I often see 185-70-14's on 240's; these have a smaller diameter than the orig. spec size for either the wagon or sedan.

Sedan original spec: 175-R-14
OK: 195-70-14 (and likely also 185-75-14)

Wagon original spec: 185-R-14
OK: 195-75-14 or 205-70-14 [or 185-80-14 if available)

"tank up sooner and possibly avoid ruining your main fuel pump"
hmm - really - wouldnt it cause damage to the in-tank pump first, being as small as it is and aso slightly raised above the tank floor

i have found that even when i push the gauge as far as it will go i still only need 14.1 gallons in the 15.8 gallon tank

i do around 340 per tank beteen fill-ups at 26.7 mpg mostly hiway miles
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big rich in arkansas '62 544 132K, 85 244 210K, 95 855 105K