View Full Version : RPMs 65, 70, 75 with larger tires
I know that several of you have put larger tires on. I would like to do that but don't want to lower RPMs too much.<br><br>If you have larger tires and the 6 speed please tell me what RPMs you are running at;<br><br>75, 70, 65. I ordered 3.73 rear end.<br><br>Please included tire size.<br><br>I guess I need a base line so if someone with stock tires would also please give their input that would be great.
I have not checked out all the speeds you listed, but I know I run 1900 RPMs at 70 MPH with 315/70/17 tires, 6 speed, and the 3.73 rearend (speed is corrected to account for new tire size).<br><br>Just a thought - the actual sizes of tires on big tires often differs from 1" to 2" by the size listed by the mfr. The major tire companies list the actual sizes of their tires either on the web or at the dealer. My tires are closer to a 34" rather than a 35."<br><br>Best to y'all<br>Bill :)
Utah,<br><br>Thanks, I pull my boat between 65-70 and don't want to shift down for small hills. I've read where 1700 rpms is the start of the sweet spot but I don't know. <br><br>At what rpm do you feel like you need to shift down? <br><br>
RLS - Shift down? Hmmmm.... don't do that much with the new truck. ;D But, if loaded and hitting a good incline, I'll go from 6th to 5th at about 1500-1600 RPMs. That puts me right back in the sweet spot.<br><br>Best to y'all<br>Bill :)
That what I needed to know. Unloaded I'm not sure downshifting would be an issue but loaded I am not sure.<br><br>If you are at 1900 rpm at 70 mph and you may be at 1750-1800 at 65 how much hill will be needed for a down shift? <br><br>With stock tires I think I read 2000 rpms equal 68 mph. That would make towing about perfect but when I crusie unloaded at 75 the rpms will be 2100-2200 and may hurt fuel milage. <br><br>Thanks for your input .
01-25-2003, 10:29 PM
:) Newbie here, how are you guys correcting your speedo for the larger tires you are putting on? I would love to put on bigger tires but an unacurate speedo is the hold back. Thanks.<br> Jason
01-25-2003, 10:48 PM
<br> :) Newbie here, how are you guys correcting your speedo for the larger tires you are putting on? I would love to put on bigger tires but an unacurate speedo is the hold back. Thanks.<br> Jason<br><br><br>Hold back no longer:<br>http://www.autotransinc.com/Recal.htm<br>http://www.abbott-tach.com/era.htm<br><br>Another alternative is to use a GPS unit, and use the speed readout on it. Mine GPS V is very accurate.<br><br>Tom Hybiske<br>
01-28-2003, 11:56 AM
Going from the 265 to the 315 was an 8.02% speedo/odo error reading...<br><br>At 65 on the speedo, I'm doing 59ish
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