So I am planning on driving my jeep from Michigan to California with three of my buddy's and enough gear to camp for about a month. Right now I average 15.5 mpg with just me in it. I have the 2.5l 4cly engine in my 99 TJ. I would love to hear all of your expert opinions on what kind of gas millage I should expect that loaded down at 60-70mph. And mainly what gas mileage have you experienced with the 4cly engine. Is mine low and could use a tune up or should I be content with what I have?
I drove my Jeep (with 6 cyl) from CA to WI and then WI to UT. The worst mileage I got was driving from WI to UT because of a bad head wind. The wind lowered my mileage to under 10 mpg. But the next day without any wind driving through the mountain on I80 in WY and UT I got over 18 mpg. As long as you don't try to run at 80 mph and keep it a little slower, you should get some decent mileage.
1997 TJ. 4.0, 5spd. 4" Lift, 33" MTR's, D30 front with ARB, rear 8.8 with ARB, 4.10 gears, KC Slimlites, Superwinch EPi9.0s, Hi-lift Jack. Trail Gear front bumper, rear bumper/tire carrier, rock sliders and steering skid.
I'm pretty sure that the 6 cylinder would get better highway miles than the 4 because with the 4 you would need higher rpms to maintain the same speed as the 6, right? At 70 miles per hour I'm just a tad over 3k rpms
I average 18-22 MPG around town and on the highway with my '97 2.5l 4 cylinder, with stock gearing/suspension and 31's. I think the lowest MPG tank I got was going 85mph for 300 miles. I got 16-17 mpg.
If you're getting 15.5 MPG, there's something wrong with either your Jeep or your driving style.
Give it a tune up and possibly an oil change (use synthetic oil), before the trip. You'll see an improvement for sure
The easiest way to improve your driving style is pretend like your brakes are really bad and need replacement when ever you drive anywhere. That way, you dont habitually accelerate up to speed and then slow down with braking power, essentially useing your gas to heat up your brake pads instead of useing it to move forward and maintain momentum. 90% of the time, when someone accelerates hard out of a stop light, I see them brake hard again at the next light infront of me. 10-20 seconds later, I roll up next to him and lightly tap my brakes to keep from rolling into the intersection, having coasted off most of my speed in neutral prior to getting to the red light. Who used more gas to accomplish the same thing?
Unless you've been running synthetic oil in your Jeep for awhile, I would not recommend switching to it now. It's great earlier in a vehicle's life, but when you switch later in its life it can lead to oil leaks. However, I do agree your mileage is way low. I get 19-22 city-hwy in my 2.5 with manual. I too recommend a good tune up and maybe even changing your transmission gear oil.