So my XJ is lifted, and mileage is at best about 15 or16 mpg at 65 mph on level highway. last trip cost 450 bucks in gasoline . so what might help from the aerodynamic way?
a roof top rear wing to reduce the vacuum behind the XJ?
How about an air dam (removable for wheeling)? Side skirts below the rockers, much like some semi rigs use, also removable for wheeling?
remove roof rack? Golly I hate the idea of my spare gas cans on the bumper, rather have them on the roof. thinking Pinto.
what makes sense, what is a silly idea?
if the savings is on the order of ten percent, it might save me a couple 100 bucks a year. (at current crazy prices) on last weeks trip, at Death Valley it was pushing seven bucks a gallon last week. I passed on that and drained my ten gallons of roof top gas cans into my XJ rather than pay that price. That saved me a bit over 20 bucks, as I got that gas at home for about 5 bucks ( 91 grade is in my gas cans, so that I may use it in my other cars that require 91 grade. for the XJ, 87 grade is the usual fuel.)
The cheapest with in a few miles of home is about $4.50 for 87 grade, but 5 bucks is often the price near me. Cant find 91 grade for under 5 bucks, i need that for some of my engines
Got to save fuel
On last trip we purposely drove slower than on prior trips, this gained us about 1 mpg on both me and friends XJ on the highway stretches . . 65 mph verses 70 mph, easy on the uphills, minimal passing, staying in the Volkswagen lane on the interstate.
Don't take this the wrong way, but you're driving a lifted brick with a loaded rack on top of all that boxy goodness. You're not going to change anything by adding wings or crap. Your best bet is reverting to stock configuration, ditching the larger tires and driving like grandma. Oh, and move out of Kommiefornia, gas prices there are out of control because idiots out there keep voting to raise taxes. We left this last year and couldn't be happier.
You are driving a barn door with a angled windshield. 16mpg is pretty good.
nothing you can put on the roof is going to help. Take everything off the roof including the factory cross bars. Drop it down to a budget boost lift height and put stock size tires and aluminum wheels on it.
16 ain't bad, but when you lift an XJ you are setting up a ton of air turbulence. When you mentioned a dam, you were right on. Might look a little unusual, but it would work
Highschool physics will tell you that it takes more energy to rotate a heavier tire. Narrower tires are lighter than wide ones, for example, a 32" tire like a 235/85/r16 only weighs about 48 lbs
Loose the roof rack and you milage will increase without spending any money
If you're getting 16 mpg....check it using a gps app on your phone (like DigiHUD)
I thought I was getting 20-22 out of mine on 31" tires.....come to find out, the factory speedo was off.....a lot.
I currently have 32" tires on it, and stock 3.55 gears.........still the factory speedo gear in the trans/t-case.......and my speedo is off by 1 mph @ 60 mph by GPS. 61 mph GPS is 60 mph on the speedo.
That means the stock one was off by almost 15%....in the wrong way
My odometer is correctly calibrated. 15 to 16 mpg was found at each of several all highway mile fill ups. I am very confidant that is a true mpg value.
We often get around 8 mpg off road on an average day of a mix of trails and crawling, this of course is VERY terrain dependant.
And a good way to carry gas - we can't let the guys driving Wranglers have all the new toys:
Mounting cans as such gives me the *****'s (jeep joke) i.e. fear of being rear ended and having that gas cans crash thru the hatch and splash gasoline inside the jeep, kaboom!💣💥 I have been rear ended in high speed crashes several times, cars totally totalled, had there been a gas can back there, it would not have been good, not that it was good to begin with, it would however less gooder still had a gas can been on the back. This happened enough that I added high mount brake lights to my car before they were mandated by law on new cars.
Stay safe.
ps... where is that, looks nice, Titus Canyon perhaps?
