Could someone tell me how much power I am going to loose if i go up in tire size from stock to to 315/75r16s. I just received the tires that i ordered and I ended up with 315s instead of 305s. I just want to know if there is going to be a serious power loss or not. Thanks

 

You'd experience a much more noticeable power loss if you went with taller tires, and these don't appear to be that much taller, just wider. You may notice a bit of power loss with the wider tread if you pay close attention, but it won't be significant.

 

if your going from stock tire size whitch is around 255 ish to 315....then yes you will loose some power....well not really power, your losing gear from the taller tires....every inch over stock you lose .10 off your gear.....will make a difference......305/70/16s are around 33 inches tall and i'm guessing the tires you actually got are 315/75/16s whitch are around 35 inches tall.....now also with 35's you may notice rubbing when turning along with a lose in gear

 

Great advice from above...Keep in mind a few things! If you ordered 305s and got 315s, your gonna need a bigger wheel. I dont know if you were planning on changing your wheels as well but 305s will fit on a stock rim, 315s your gonna need a rim that is at least 8" wide...your stock is only 7.5" I believe. And trust me...you will notice a big power loss, or as said above, a GEAR loss with 315s (35s). I have 35s on my truck...you prob have a stock 3.55 ratio like I do...and the 35s dropped my ratio down to about a 3.20 or so. 33s wont be as bad, but your truck will become much more of a "dog" so to say. With 35s your gonna need a small lift, prob 3" body, or something. My next thought...Im in the process of going to 4.56gears, with my 35s, that will put me at about a 4.10 effective ratio, you wont have the "peppiness" that had before and it will feel like it takes you longer to accelerate and get up to power!

 

Most people tend to ONLY consider the effective gear ratio change when considering the effects of large tires. That is only PART of the picture.

The added weight at a larger radius GREATLY increases the amount of energy that it takes to turn those four big FLYWHEELS. The effect is SIGNIFICANT. Tires of the size you mention typically weigh close to 70 pounds and most of this weight is at a larger radius than the original tires.

Big tires look cool, but they cost SIGNIFICANTLY in lost power and increased fuel cost.

Good luck,
Doc

 

WEFITE4U...MBDiagMan is absolutely right! I forgot to mention that myself when talking about the "effective gear ratio." Weight of the tires...and ALSO the height of the truck will affect the power loss! Depending on how high you go..."wind drag" also plays a role in power loss. Best of luck!

 

Flywheel affect. Harder to get rolling, harder to stop. It'll look mean though!

 

My gears are 3.55 and my stock tire size is 265/70R17 on 17x7.5 rims. What i am looking at going to is 315/75R16 on 16x10 rims. I know that the ProComp Xtreme Alloys i have weigh considerably less then my stock rims. That and the new tires are only 3 inches larger then the tires that came on the truck. Am i really going to regret this decision when it comes to gas mileage and performace?

 

i've got 305/70/16's on my truck and i went from 255's.....it is a difference in power but i didn't notice a difference in MPG....i got 18 before and i'm getting between 17 and 17.5 now....gearing yes....you lose some gear and you will notice that especially on hills but the looks outweigh the problem especially when you just have to regear the truck to gain it back again

 

Agreed...looks will definately outweigh the performance loss etc. Ive got 35s on 16x8 American Racing rims, yah I notice a difference in acceleration etc...but the looks are well worth it, plus its a good reason to now get a set of gears

 

And don't forget about your steering system, puts a strain on your pump, rack, tie rods, ball joints, control arms, and if something breaks because of that it will not be covered under any factory or esp warranties. If you know someone that knows what they are doing they can change suspesion angles, camber, caster, toe, so that it will not put so much of a strain but will not ride down the highway as easy due to a lack of caster.

-Ryan

 

Just ran some calcs. You didnt say what your stock tire is. Seems alot of people think there is only one stock size but there are atleast 4 different stock sizes I know of and probably more.

Assuming stock = 255/70/16 and going to 315/75/16
your going from a 30.1" to a 34.6"
your going from 671 revs/mi to 583 revs/mi
your speedometer/odemeter will read 15.1% too slow
when you speedo reads 60mph you will be going 69.1mph

Didnt know if any of that was useful but there it is. Without changing gearing that will be a fairly large jump. 15% diff in drive ratio, plus alot more weight, and more drag on the road due to tire width...

 

My stock tire size is 265/70R17. That make a three inch difference. I figure i will put the 315/75R16s on and see what happens. Regear in a few months and just go with it.

 

WEFITE4U...YOu wont regret it...it will look nice! Im sure you know, but you will need a lift to fit 35s...a 3" body will be sufficient!

 

With the 2" lift I put on mine (suspension) it looks like it could easily fit 35's, but the width I am not sure how much wider it could go. To bad that thier isnt more options in the 34-35" range for skinnier tires. But I dont want to put money into gears, and my v6 probably wont handle much bigger than the 285/75 I got on it.