kyncl

Does the size of tire affect your dyno numbers?

06RAM2500

Depending on how big, but it could affect it by more than 5hp and 8-12 lb/ft of torque. Bigger tires will take a little more to get rolling.

powermad

the rotating mass will mainly effect daily driving such as accelerating, breaking and handling it will take your truck longer to get moving but when on the dyno the tires are already spinning at around 55mph so they wont have really any restriction so i doubt it will do anything. thats a guess. now im interested to see someone with a huge lifted truck with 48 inch tires dyno with those and then again with a set of 265's

Tate

Big tires add a lot of rotating mass, and whether you are stopped, or going 55, if you on an inertia dyno, thats more mass to accelerate, thus robbing hp and tq. That being said, its still accurate. If you put two identicle trucks side by side, one with big 48's and the other with stockers, and had them geared so there effective gear ratios are the same, I'd still expect the short tired truck to be quicker, just because there is less rotating mass to get going.

powermad

yes i agree it would be quicker on the street off the line with smaller tires but on a dyno the restriction is already moving so wouldnt that not affect a truck that stock has over 450 ftlbs. my buddy has a 2005 dodge cummins with 52s on it and a smarty on 9 and edge comp turned up all the way he put down 430hp i dont know alot about the 3rd gens but that number looks respectable to me. i should get a hold of him and have him put stock tires on it and dyno. anyone out there have easy access to a dyno and can test this fact???