Does anyone have a directional idea of what the speedo correction factor is if you running 33" tires??
What is on the door is usually the very base model size and not the size it may have been optioned with.Also, if you don't install the new speedo gear and you have the stock speedo gear, you can manually calculate it by figuring out the circum. % difference between the stock tire (printed on the door VIN label) and the 33" tire.
So if the 33 inch tire happens to have a 15% larger circum. than stock...then when you calculate MPG (miles/gallon), you want to add that 15% back in to get a "better" (not perfect) calculation.
2-3 MPH off... not that bad I agree...I run 33X12.5X15 and compared to GPS speed I'm only showing 2-3 mph slow on the speedo. Its not worth changing.
Just exercise care on the re-seating the gear and keeping the O-ring intact.Changing the gear takes all of 5 minutes. Its super easy. Follow the directions on the link by Unlimited. Ive got mine in a box waiting to go on the jeep next week. It sits in the garage with the tires and wheels and ZJ springs. I need to get on the ball and straighten up my garage. LOL
Did the GPS test today .....2 to 3 MPH at 15 MPH maybe. I'm 16% off that's a big difference at 65 MPH. I've calculated with GPS. I have 33's also.
Just out of curiosity, what tires are u running ? I know you said 33sJohnrmclean said:Did the GPS test today .....
@ 30 doing 31
@ 40 doing 42
@ 50 doing 53
@ 60 doing 63
@ 70 doing 74 ..... you get the idea
not as much difference as I expected considering the tires sound like I'm doing 110 all the time :whistling: