VX Transmission and Cruising RPM's
 

I read the thread about VX's cruising RPM's being around 1900 - 2000 at 60mph. My VX is currently doing 3000 RPM's at 65mph with a tire size of 195/50R15. The car does have a high idle issue. My question is, does the idle issue effect cruising RPM's or do I have a DX or SI tranny?

try this tool out:https://www.fatboyraceworks.com/gears/

you'll have a ball with it..

But to answer your question... when plugging in your numbers, it would suggest that you should be going 88mph (Back to the future anyone?) if you really are in 5th gear.. By the looks of it, you have an Si transmission... Or... you're not actually in 5th gear.. BTW do you have lean burn on that car? Also if you really do have HX rims, then they're not 15" but 14"... VX rims are 13".

I have 4 sets of wheels. The ones that are currently on are 15" konig feathers. Yes it does have lean burn, weather its working or not im not sure. Sometimes I feel it engage but it could be all in my head. As you can see im getting less than stellar gas mileage.

Well just keep in mind that your odometer is seriously off as well with those wheels so that could be hurting your calculations as well. Car originally came with 165/70 R13. If you plug in those numbers and compare it with what you have, you can recalculate your actual mileage. In other words, you're going faster & further than the speedometer & odometer indicate.

When I plug in the two tire sizes, they both equal out to 22.68", with the VX tranny the two graphs and speeds are identical.

No it's not, I already did the calculation. Play around with the tool a little more and you'll see the numbers change. Make sure you have Javascript enabled.