View Full Version : getting the best mileage out of the 307


ReagansRollsRoyce
01-06-05, 08:51 PM
Somewhat related to the 21 mpg post below but different enough so I decided to start a new thread.

In my 87, i get anywhere from 18.5-21.5 mpg on the highway.

2 questions

1.) (might be kind of a toughie) if you are in cruise control, what speed do you think provides the best fuel economy? 55, 65, 75?

2.) if the highway on which you drive has some hills, but not big ones, is it more efficient to go in cruise control despite the occasional downshifts to 3rd on steep grades or better to stay in overdrive and slow down 5-10 mph on the grades without downshifting...in short...is steady speed or steady throttle better on gas?

This is more curiosity than anything else, I know I won't get incredible mileage driving a big Cadillac! :)

davesdeville
01-06-05, 10:06 PM
Find out the torque peak RPM for your engine. Then use a calculator you can find online and input the gear ratio for the highest gear in your car and the final drive ratio to calculate the speed at the torque peak RPM. Aim for a couple MPH under that.