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Paul · 03-13-2006

Kurt,

I can't speak for the Ascona w/ auto, but a 1975 Manta w/4-speed was rated by the EPA @ 19 mpg in the city and 27 mpg on the highway. BAck when the Federal Speed limit was 55mph, I used to get 28 - 30 driving at 63 mph on the interstate.

Somewhere I've got an old Car and Driver with a 6 car comparision that might give the EPA numbers from back then, but the car was a manual tranny.

I think 21 mpg is a little low. The 75 FI model used a "Special" thermostat. If you are using the standard looking thermostat, then the water never heats up to the proper temp and the car will run a bit on the rich side. The injector pulse width is tied to the water temp by a negative coefficient temperature sensor. So the water needs to be at 195 for the car to fully lean out at normal operating temperature.

Also, I'd bump the timing up a couple of degrees, try 5 degres advanced. Also, I'd change out the rear end grease with a synthetic, like Red Line. I'd also run a full synthetic motor oil. I'f you don't want to go that route, I would run 1 QT of Moble 1 with what ever regular oil you use. Maybe the best way to improve milage would be to throw out the points and get a Pertornix.

With these few things you should be able to eak out a couple more MPG's

Good Luck

03-13-2006	#3 (permalink)
Paul Member 1000 Post Club Join Date: Mar 2002 Location: Ft Smith, Arkansas Posts: 1,481	Kurt, I can't speak for the Ascona w/ auto, but a 1975 Manta w/4-speed was rated by the EPA @ 19 mpg in the city and 27 mpg on the highway. BAck when the Federal Speed limit was 55mph, I used to get 28 - 30 driving at 63 mph on the interstate. Somewhere I've got an old Car and Driver with a 6 car comparision that might give the EPA numbers from back then, but the car was a manual tranny. I think 21 mpg is a little low. The 75 FI model used a "Special" thermostat. If you are using the standard looking thermostat, then the water never heats up to the proper temp and the car will run a bit on the rich side. The injector pulse width is tied to the water temp by a negative coefficient temperature sensor. So the water needs to be at 195 for the car to fully lean out at normal operating temperature. Also, I'd bump the timing up a couple of degrees, try 5 degres advanced. Also, I'd change out the rear end grease with a synthetic, like Red Line. I'd also run a full synthetic motor oil. I'f you don't want to go that route, I would run 1 QT of Moble 1 with what ever regular oil you use. Maybe the best way to improve milage would be to throw out the points and get a Pertornix. With these few things you should be able to eak out a couple more MPG's Good Luck __________________ Paul Last edited by Paul; 03-13-2006 at 09:30 PM.