My dad is wanting a programmer for his 96 XJ. Which one would be the best for adding power? I've seen only a few for the XJs. He wants more power to turn his 33s on 3.55 gears. Or would his money be better spent on 4.56s? TIA

 

Buy the gears. Programmers won't do anything to for his 4.0.

 

X2, you'll get more from a gear change than you ever will with a "chip".

 

Thanks. He's worried about MPGs too. I know his city MPGs will increase but how about his highway?

 

If you re-gear the axles to compensate for the bigger tires, the mileage will get much closer to 'stock' for city and highway. That is unless you go insane-O and try to stuff something really low in there. I am pretty sure you will be just fine if you go "middle of the road" with the gearing. Not too high and not too low, just something in the middle. I think 4.56 is the recommendation for his set up.

 

Alright, thanks for the info guys.

 

4.10s work nicely with 33s.

 

I was just messing with a gear calculator and found that 4.10s will set the speedo back to stock so I may have to get him 4.10s instead