I've seen a lot of about gear ratios and how its helpful to go "bigger" than what your change in tire size would be, i.e. use 4.56's when you have 33" tires even though 4.10's would be the closer match.
I would like to ask this a bit differently with an example. I have 2 XJ's. An 01 XJ with 235/75R15's on factory steelies, stock suspension, and stock gears. I also have a 97 XJ with 30x9.5x15's on factory alloys, a 2.5-3" lift, and stock gears. Both have BFG A/T tires. I bought the 97 XJ with a lift and have no stock comparison. What I do notice, is that climbing grades the 97 XJ seems to have "less power". There's a hill I've climbed both with on multiple days (trying to account for any wind) and the 01 XJ climbs it easier than the 97 XJ, and seems to have a higher top speed too. Both seem to have about the same compression. The 97 XJ has a new cat, etc. Out here in Colorado with the high altitudes its not uncommon to run either in 2nd gear near redline on some of these highway grades once you're near/over 10,000'. However, the 97 XJ seems to need 2nd gear a bit more. How much of this could be attributed to the lift/larger tires versus overall powertrain/drivetrain performance.
And, if I do say put 4.10's in, am I likely to "loose" top speed because obviously if I need to be in second near redline, I'm not going to be able to go as fast. Or would the 4.10's eliminate the need to use 2nd gear so its not really an issue.
Because regearing takes time and isn't cheap, I would like a bit more information before I pull the trigger.
Thanks!
I would like to ask this a bit differently with an example. I have 2 XJ's. An 01 XJ with 235/75R15's on factory steelies, stock suspension, and stock gears. I also have a 97 XJ with 30x9.5x15's on factory alloys, a 2.5-3" lift, and stock gears. Both have BFG A/T tires. I bought the 97 XJ with a lift and have no stock comparison. What I do notice, is that climbing grades the 97 XJ seems to have "less power". There's a hill I've climbed both with on multiple days (trying to account for any wind) and the 01 XJ climbs it easier than the 97 XJ, and seems to have a higher top speed too. Both seem to have about the same compression. The 97 XJ has a new cat, etc. Out here in Colorado with the high altitudes its not uncommon to run either in 2nd gear near redline on some of these highway grades once you're near/over 10,000'. However, the 97 XJ seems to need 2nd gear a bit more. How much of this could be attributed to the lift/larger tires versus overall powertrain/drivetrain performance.
And, if I do say put 4.10's in, am I likely to "loose" top speed because obviously if I need to be in second near redline, I'm not going to be able to go as fast. Or would the 4.10's eliminate the need to use 2nd gear so its not really an issue.
Because regearing takes time and isn't cheap, I would like a bit more information before I pull the trigger.
Thanks!