Dunzready

Hey guys I will be driving from Virginia to California next month with a small trailer and dont want to spend my life savings on fuel. Any Ideas? I already have Cold air intake, Headers, high flow cat, and a Flowmaster muffler. What else can I do?

freegdr

run high octane air up tires and good wax job

Sgt Sleepy

Rent a car LOL! You've down all the right things. Now change the oil, clean the filter, check the radiator, and top off the tank. Come on out lemme know when you're close. We live in Fresno/ Yosemite area . Would be cool to cruise with ya!

repair

High Octain does not increase fuel mileage

freegdr

also dont use cruise if you have it greatly reduce mileage

freegdr

high octane burns more efficently tha lower octanes more efficency less fuel need for power

robertj

Seriously, pulling a trailer, the best thing you can do is drive about 60 MPH. I was lucky to get 10 or 11 MPG towing my 6'x12' enclosed trailer (it's around 7 or 8 feet tall) at 70+ MPH. Dropping down to 60 MPH would bump the MPG to around 13 or 14 MPG, but I couldn't stand to drive that slow in the Interstates.

tjwalker

Your mods will help.

Be sure that your tuneup hardware is FRESH. That includes plugs, plug wires, distributor cap, rotor. A bottle of quality fuel system cleaner can help optimize fuel injector spray pattern. I like BG44K and Techron. Skip the cheapy crap that lines the shelves of wally world.

Regular gas is fine for a stock 4.0, skip the premium.

xjdirtbath

Ship the xj and rent a prius. You'll fit right in with the cali crowd but u may get linched halfway accross.

blahblah718293

yeah its up in the air about higher octane, but this is a good chance to try it, and get back to us with solid number results.

as for everything else, airing up the tires to about 35 may help but i wouldnt go higher than that. also drive slow, id propably do 55-60 the whole way, thats probably the best thing you can do. i wouldnt spend 100 dollars or whatever on a full tuneup unless its really due, if your doing it just trying to get better mileage, that 100 dollars can buy about 33 gallons of fuel, to take you about an extra 550 miles (with my 16mpg)

also: try to pack light. every pound counts.

hennigm4

cruise control and reg gas will help regardless of what has been posted. Do your own research.

Air pressure in tires and a tune up will help, but expect 15-18 MPG regardless of what you do.

Caish

Seriously,
you can rent a car for $30 a day, I would bet you could pay for it in the gas you save and you have the peace of mind if it fs'up its their baby.
I started renting cars for trips after the S15 Jimmy blew a tranny 500 miles from home. The money I spent going after it would have paid for the rental car 3x over.
Do a tune up and make sure the timing is set as advanced as you can get without it pinging or being hard to start too.

tjwalker

Base timing for the 4.0 is controlled by the computer; not adjustable.

vtfd330

think about changing your tps...as preventative maintenence, i just replaced mine....HUGE difference!!!! also check your throttle body studs...mine were not tight, torqued them to spec and topped off the tank with mid-grade gas....so far, this fill-up, i've managed to drive 83 miles on a little over 1/8th of a tank!!!! it's blowing my mind!!! 4.0 with auto trans on 30x9.5 tires.

notop46

Remove the four bug catchers on the roof (plus roof rack and/or cross bars), air up the tires to 35 PSI, (swap to skinny tires if you have them), tape the body seams, drive like your grandmother used to (or still does).

Higher octane fuel has fewer BTUs per gallon. If you run higher compression, or more advanced timing, you will get better mileage and need the extra octane to reduce/eliminate pre-ignition and detonation (both bad). If you notice any pinging climbing the mountains, bump up a grade to prevent it. Otherwise, stick with regular.

Have a safe trip.