RPM's W/Gears & Tires
 

Can anybody tell me what the rpms would be at 65 mph with 33 inch and 35 inch tires with 4.56 gears with the 5.4 and automatic tranny?

With 33" tires and the 4R75W trans/5.4L 3V/4.56:1 combo, the RPM at 65mph would be 2113. With 35" tires and the 4R75W trans/5.4L 3V/4.56:1 combo, the RPM at 65mph would be 1993. See the images below:

http://www.superdutyonline.com/images/33.jpg

http://www.superdutyonline.com/images/35.jpg

All kinds of calculators exist on the internet to figure stuff like this out. For instance, I happen to know that the 5.4L equipped F-150's have the 4R75W trans, so I Googled the final gear ratio (.70), punched in the tire height (in inches), the speed (in MPH), clicked the button next to RPM, and then clicked OK. That's what I came up with. I prefer that particular calculator because it has a GUI, and because my friend is the one who made it. See ya! :coffee:

EDIT: I fixed it! :p

actully the final gear is 0.7. (Overdrive on the 4R75W is .7 not .84) so your Rpm's would be lower than that..

My Rpm's at 65mph are at 2200-2220 with 4.56 gears and 33's (5.4 and 4R75W) .70 final drive!

thats actually pretty helpful i appreciate your guys' replys.......i was just seein if id be under the 2000 rpm mark like in my explorer...something about being below that mark that makes me FEEL happy about gas milliage lol....and 4.56 and 35 is what i intend to go with