Amazing 3 MPG Increase

[XDGT03]

We regularly see questions on this forum about how to increase gas mileage. Suggestions have ranged from changing plugs, wires, air filters, fuel filters, fuel injector cleaner, etc... I have done all of these, not to increase my fuel mileage but because they needed to be done as a part of routine maintenance. The result has been exactly 0 mpg increase in fuel mileage. This is a 1998 GC with a 3.3L flex.

However, with fuel prices north of $3.00 per gallon for regular (not E85) I decided to try another way to increase my mileage (18 mpg from about the day we got it). I decreased my avg speed especially on the highway from 80-85 mph to around 73 mph. This has netted me 3 mpg avg.

[bw03]

That's nothing new. It has always been known that slower speeds saves gas but thanks for confirming it. It probably won't make me slow down much though.... :)

[RickMN]

Trivia factoid: Increasing speed to 65mph from 55mph increases aerodynamic drag by 36%.

[otis24]

When I go to "town" (120 miles one way), I drive 65 MPH rather than the max posted limit of 75 MPH unless I have an appointment to keep. I see a dramatic difference in fuel consumption.

[mfahey]

Another tactic is to draft behind a semi(not too close for safety reasons). This gets me 4-6mpg according to the instantaneous readout.

[mf360]

That's true, but you will get best gas mileage by keeping RPM's at lowest speed and engine in the powerband (where it makes the most torque).

[bigwobbely]

85!!!!! death wish!!!