Fuel Saving Tips

Modding your off-road vehicle: what to expect

If expectations are in line with reality, unhappiness is avoided. When modifying a Jeep or other SUV, keep in mind: - 2 highway mpg for Roof Basket [reduced aerodynamics] - 3 highway mpg for Larger Tires (1.5 inches taller than stock in my case; suspension lift may be required to run larger tires) [taller tires reduce mechanical advantage, like running in a higher gear. Larger tires are also heavier. Results will vary.] - 1 highway mpg for adding steel skid plates, rock sliders, bumpers, etc. [extra weight] There is a trade-off between mpg and off-road prowess. This trade-off can be partially overcome by spending even more $$$: +2 highway mpg for Re-gearing the differentials (e.g., from 3.73 to 4.10 ring & pinions). This mod can regain your rig some power and mpg if you are running tires 1.5+ inches taller than stock, but will decrease mpg with the stock tire size. [increases mechanical advantage, offsetting larger tires. Results will vary.] Example: V6 Jeep Liberty with roof basket, 4 inch lift, larger tires (245/75/R16; stock 225/75/R16), but not yet re-geared: Stock Configuration: 14 mpg city, 22 mpg highway Modded: 11 mpg city, 16 mpg highway