Larger tire size but less weight. Discuss!

[BellevilleRam]

Hey folks. I need advice on buying larger but lighter tires tires vs smaller diameter but heavier tires for potential performance gains. I'm currently running Falken Wildpeak tires which are E rated 35x12.5 x 17. I've been wanting to get more forgiving C rated tires and was considering also dropping down to 33" for the weight savings and to help my 3:55 gearing out.
My dilemma is that I have always wanted to put 37" tires on my truck for ground clearance and for the looks but don't want to make my acceleration and braking even worse.
I saw that BFG has C rated KO2'S in 37x12.5 x 17 which weigh 42.24lbs LESS than my current tires for all four.
My question is, if I went to a 2" larger diameter 37" tire but reduced the rotational weight by a combined 42.24 lbs, would the 37's still affect my trucks performance negatively vs my current heavier 35's?

I guess I'm trying to convince myself that I can run 37's without getting any worse acceleration and overall strain on the gears etc than my current 35" but heavier tires.
Would things kind of even out? Are the lighter but larger tires better or worse than driving with smaller but heavier 35" tires? Hope this made sense! LoL

 

[crazykid1994]

I cannot give you a 100% definitive answer but what I’ve been told is larger tires no matter what the weight will reduce your performance because you’re increasing the actual circumference of the tire which changes the effective gearing to the ground. Lighter tires will reduce the actual effort to turn but larger will probably negate that reduced weight. I’m eyeballing a set of 285/75r18 cooper discoverer at3 xlt tires when it’s time for my swap. Current is 305/70r18 Mickey Thompson atz p3. The mickeys weigh 71lbs per tire. The coopers weigh 59 lbs per tire. 12lbs reduced rotation mass per tire. They are both 10ply E rated tires that measure 34.75” tall. I’ve been trying to find a c or d rated in either size for a lighter tire but no luck.

 

[BellevilleRam]

It would be great to see a chart for tire size vs weight performance characteristics! How larger tires in a lighter weight affect your vehicle vs smaller but heavier etc.

 

[augiedoggy]

Weight matters as much if not more than an inch or two of height but they both matter. I'm waiting on backordered 295/70/18 nitto 4 ply terra grapplers which weight 51lbs per tire to replace my 70lb MT (also 295s) because my fuel mileage absolutely sucks now with my tuned ecodiesel and 3.92 gears and 8 speed trans compared to the 31.5" 43lb nittos I had before. still plenty of power but I lost 10mpg on the highway and like 7mpg overall. truck also rode way better with the 4 ply tires. I do not need 10 ply any more than I needed the 2500 series truck that they normally come with. Other factors like tire tread type and width also impact all this. this is why the smarter older truck guys often run narrow tires

Ive told this story before but I had a wrangler years ago (4cyl) 4.10 gears and a manual 5 speed. I bought it with 4ply kelly safari AT tires that were 31.5" tall. I drove it for years and then installed BFG 32.5" MT tires (10 ply). From that change alone I literally could no longer hold speed in 5th gear anymore and my mpg went way down. once I regeared to 4.56 life was great again but my point is 1" in height and the much larger weight increase made a huge negative change.

 

[BellevilleRam]

Then there's the factors that less unsprung weight brings to the table regarding performance! Especially when it comes to suspension.

 

[retired]

circumference is what kills power. It essentially changes your gear ratio to a lower number numerically. your stock 3.55's will be like 2.84 gears. bigger tires regardless of weight will kill accelleration if the gearing is not changed to compensate.

 

[BellevilleRam]

Thanks for the feedback gang!

 

[DILLIGAF]

My Lifted truck on 37s does the 1/4 miles in 15.9 sec even after all my MODs, Cam swap , TQ , 4.56 gears ... ect ....

August 8, 2021

youtu.be

 

[BellevilleRam]

My Lifted truck on 37s does the 1/4 miles in 15.9 sec even after all my MODs, Cam swap , TQ , 4.56 gears ... ect ....

August 8, 2021

youtu.be

I'm not into racing. I assume that time is bad? LOL

 

[crazykid1994]

My Lifted truck on 37s does the 1/4 miles in 15.9 sec even after all my MODs, Cam swap , TQ , 4.56 gears ... ect

I'm not into racing. I assume that time is bad? LOL

Given that my truck stock on AT tires went 15.2 to the 1/4 mile yea. That’s not very good. Not bad but not good. I need to get back to the track with mine to see how it does 6.4 manifold, long tubes, catback, tuned, and 35s. Definitely feels faster. Maybe high 14s? I can tell the 35s are definitely dragging me down. Hence why I’m looking at the lighter 285/75r18

 

[DILLIGAF]

That’s not very good.

It is for my setup... lol. Fastest Winch down that track....

 

[augiedoggy]

circumference is what kills power. It essentially changes your gear ratio to a lower number numerically. your stock 3.55's will be like 2.84 gears. bigger tires regardless of weight will kill accelleration if the gearing is not changed to compensate.

in my case I have the optional 3.92 gears... with the 34" tires my rpms should still be comparible with the 3.55 gears and stock tires... thats not the case however. The rotating weight makes a large difference

 

[BellevilleRam]

I've decided to drop down to 33's. Specifically, the BFG KO2 LT285/70R17C which for all four tires will be 100.28 less lbs of rotating weight than my current 35" Falken Wildpeak tires! Wow! That should be quite noticeable!!!

 

[Regcabguy]

Hey folks. I need advice on buying larger but lighter tires tires vs smaller diameter but heavier tires for potential performance gains. I'm currently running Falken Wildpeak tires which are E rated 35x12.5 x 17. I've been wanting to get more forgiving C rated tires and was considering also dropping down to 33" for the weight savings and to help my 3:55 gearing out.
My dilemma is that I have always wanted to put 37" tires on my truck for ground clearance and for the looks but don't want to make my acceleration and braking even worse.
I saw that BFG has C rated KO2'S in 37x12.5 x 17 which weigh 42.24lbs LESS than my current tires for all four.
My question is, if I went to a 2" larger diameter 37" tire but reduced the rotational weight by a combined 42.24 lbs, would the 37's still affect my trucks performance negatively vs my current heavier 35's?

I guess I'm trying to convince myself that I can run 37's without getting any worse acceleration and overall strain on the gears etc than my current 35" but heavier tires.
Would things kind of even out? Are the lighter but larger tires better or worse than driving with smaller but heavier 35" tires? Hope this made sense! LoL

Putting C rated tires on a full size truck is a death wish. Regearing will restore your factory powerband and would lessen the performance hit you get with bigger,heavier tires.

 

[BellevilleRam]

Putting C rated tires on a full size truck is a death wish. Regearing will restore your factory powerband and would lessen the performance hit you get with bigger,heavier tires.

Not sure why you think C-rated tires can't be run on a Ram 1500 as MANY trucks are out there running them including the Ford Raptor that comes stock with them. Unless you drive on very rocky terrain at high speeds often, a C-rated tire is more than adequate. An E rated tire is overkill on our trucks and ride like ****, even with my custom tuned Fox 2.5 suspension. As for re-gearing, that would require an entire new front axle assembly for my truck due to the welded pinion ring I believe I read here somewhere.

 

[crazykid1994]

Not sure why you think C-rated tires can't be run on a Ram 1500 as MANY trucks are out there running them including the Ford Raptor that comes stock with them. Unless you drive on very rocky terrain at high speeds often, a C-rated tire is more than adequate. An E rated tire is overkill on our trucks and ride like ****, even with my custom tuned Fox 2.5 suspension. As for re-gearing, that would require an entire rear axle assembly for my truck due to the welded pinion ring I believe I read here somewhere.

Front differential on 4wd. Not rear axle.

 

[crazykid1994]

Putting C rated tires on a full size truck is a death wish. Regearing will restore your factory powerband and would lessen the performance hit you get with bigger,heavier tires.

Stock express 1500 and truck came with passenger tires. Not even LT tires. This is the specs on the stock Goodyear wrangler sr-a

 

[Mister Luck]

Have each of your wheels dynamically balanced any wheel that goes beyond 3oz replace that tire or rim.

install a peddle box or similar device.

Look for Z rated tires

 

[BellevilleRam]

Front differential on 4wd. Not rear axle.

Thanks for clarifying! I edited the post now.

 

[Ram Night]

I'm not into racing. I assume that time is bad? LOL

Anything over a 12 second quarter mile is a pouch.