intake ?'s

[junkjeep]

I ended up with a 99 intake and I am wondering if it is worth changing from the 93 intake to the 99. If there isn't a large gain in power or are there any advantages as far as fuel economy? I'm running a 93 xj 4.6 stroker and getting about 17.5 miles to the gallons on the highway which is close to what I got when it was stock. My friends 99 xj gets about 23-24 under the same conditions. I just wondered how much is due to the new intake design.

 

[rsalemi]

My 89 stroker gets 15 - 16 MPG around town and 21 - 22 on a highway trip (300 miles - 70 MPH) which is 1 MPG less than the stock 4.0. The 91 - 94 manifold has the shortest runners resulting in the higher peak torque RPM so the 99 manifold Should? result in lower torque peak and better mileage. But I havent't installed mine so can't prove it. Maybe somebody else has?

 

[DeftwillP]

Somebody on JU is going to dyno one. He owns a zj, but it still has the 4.0.