But skip anything about a C-101 connector...you don't have one.

 

By semi tune up I ment I did everything but plug wires. (went available at the time and never got around to ordering.) and I'll do the tips in the morning, thanks!!

 

The swap to 746 injectors gained some MPG for me, as well as performance.

My '87 loves 76 gas. I've ran everything from budget gas to Chevron and Shell but it gets at least 3mpg better and runs better on gas from the 76 stations.

 

When I got 32s, putting in the right Speedo gave me better fuel economy. Or rather it read properly lol. Added another 30-45 mikes a tank before the light comes on

 

What you have is what you get. I get 11.5 miles to the gallon mixed town and freeway driving with the AC on according to my latest fill up. 2001 XJ, 4.5 inch lift, fresh tune up, 32s, 3.55 gears, lunch box lockers front and rear, every U joint replaced in the last 6 months.
Our XJs are driving bricks, not exactly airodynamic lol

 

I got 19.6 on my last tank.

Box stock, of course , so I know it's not a direct comparison. I just had to rub that in.

 

You lucky bastard. Bone stock and I get 17 no matter what. Towing my grandpa's boat 17. Running to work and back 17. 400 miles down the freeway 17. About the only time I don't get 17 is when I'm running in low range on the sand all day. Then it goes down to 12 or so.

 

My son has a '99 sport with 31s and a 4.0. We took a trip to the school he will be going to in the fall. 88 mile round trip. 12 gallons of fuel!
We will be going through each of these steps and posting the results. Thanks for all of the documented knowledge!
irmachinist
Dublin Tx.

 

I switched from 31" BFG AT mounted on heavy wheels, to Cooper AT3 'P' version of 31" (265-75-15) mounted on lighter ravine wheels.
Performance improved, quicker off the line, accelerates better, passing on highway is easier and MPG increased.
Stock 3.55 gears.

 

Like Steve said you have a gearing problem for 31" tires it needs 4.10 gears to get the MPG where they should be, really the only.


I have a 99 with quite a few mods 4 1/2" lift, after market bumpers (Heavy), roof rack homemade, armor, with about 140-160# in cargo area all the time. I run 33x12:50x15's on heavy steel wheels with the proper gear a 4.56 and get 16-18mpg with it same 4.0/AW4/NP231.


Before the gear change I ran 31's and the 33's with the 3.55 gears and it sucked plus the trans was up/down shifting all the time along with overheating.

 

Turn off the A/C is bad advice as at any speed above 35 the wind drag uses more horsepower to overcome than the A/C compressor consumes.

 

Right now I'm sitting at 31s with aftermarket front and rear bumpers (steel) and including all the mud stuck god knows where this is one heave son of a gun. Also stock gears.I leave Thursday so I don't have much time nor cash flow. (Attending college with not one loan kinda sucks up all the fun money) I'm just gonna roll with it and deal with it haha

 

Where did you get the gear set?
i_r_

 

Rustys Off Road under $500 complete D30/Chy 8.25 4.56 Motive gears and excellent master install kits included.

 

Try the vendor forum, great prices and customer support.