Effect of lift kit on gas mileage

[oldtamiyaphile]

Originally Posted by Ecky

I'm sure the lift didn't help - it increases frontal area.

Yes, but going to a 2" taller tyre gives you ~200rpm less on the highway.

[Baltothewolf]

Originally Posted by oldtamiyaphile

Yes, but going to a 2" taller tyre gives you ~200rpm less on the highway.

The massive weight increase offsets this. Big time.

[oldtamiyaphile]

Originally Posted by Baltothewolf

The massive weight increase offsets this. Big time.

Based on towing a 1000lbs work trailer with a small car in the city over a couple of years, weight has virtually no effect on fuel economy. Weight is just a store of kinetic energy, it's like a 100% efficient hybrid system. My new van is the size of a Ford E series, and I'm starting to regularly see 40mpg city, 50 on occasion if the lights are kind.

There are too many variables in this for any real meaning.

1. Increase in suspension height (aero drag)
2. Increase in tyre width
3. Going from a low resistance street tyre to a high resistance off road tread
4. Normal loss of economy associated with new tyres (often reported as -2mpg even when switching to eco tyres)
5. Possible loss of TC lock up at lower speeds
6. Lower RPM on the highway?