A place for more technical discussions. Please make sure you post in the correct section on the site, this way it keeps the site tidy AND ensures you get a more relevant answer.
Saxj: I needed to edit my post a little. I realized I was using my transfer case ratios (automatic with 1.32 ;1) when I initially calculated the RPM figures. I must have been infected by Suzuki.
I started out with nothing & still have most of it left
stock size on the old is 205/70R15.
stock size on the new is 195/80R15
The difference is 3.7%, which if the gearing were the same, would give roughly 3860 RPM for the new one at 120kph (given that the old is 4000rpm at 120kph)
Which means there must be some difference in gearing.
Agreed. The 2 stock tire sizes wouldn't make a significant difference in RPM. That is why I mentioned the 30 inch tires. It would need to be more extreme to see the difference you mentioned.
I haven't done much review of some of the older ratios. Pre 2005 ( I think ) had different ratios. If your older Jimny was pre 2005, you would want to review those too. In truth though, I don't think you will find much difference when it comes to the RPM at speed. Especially when your older car matched what should be.
I would still suggest manually checking if you want to be sure.
I started out with nothing & still have most of it left
