I just got an '04 and it turns 2,000 rpm @ 80mph with stock size tires. Does this mean a previous owner swapped to 4;56's?
4.10 gears @ 80mph = just over 1600rpm in 6th gear...seems you're a couple hundred rpm off bud 4.10 gears @ 75mph = 1500rpm in 6th gear... My truck has stock size tires (305-40R22's)
Make sure you take tire diameter into consideration!! 45 series will throw off calculations. Also someone with new tires versus old tires. Does make a slight difference. Ill see what mine says. I have 45s out back and 40s up front.
You're kinda right... If you are getting your mph reading off of a GPS, then yes it will throw it off. Although if you are running 45's, you will be going faster but your speedometer will not know the difference.
A GPS will show the correct MPH regardless of tire size. The speedometer will read differently with a change in tire size. Ya'll do realize that calculating RPM, speed, gear ratio, flux capacitor readings, etc, is as simple as using a basic calculator (click here for an example), right?
Me too, Cody. Check your RPM in 4th gear for a couple different speeds and I bet the numbers work out for a 4.10 though.
Lol. Sorry bud I knew what I meant just may not have sounded right. YES, your GPS will read true. But what I meant by your speedometer not knowing the difference is... if you have 40 or 45 series tires your speedometer "for say" will read 120 @ 6000rpm, yet with 45 series you will actually be traveling faster. I realize you know this, I just had to post this to reassure myself that I'm not quite as dumb as I made myself sound! MERRY CHRISTMAS GUYS!!! Thanks for all the helpful info and entertaining threads on my first year with the VTCOA!!!