Tire Weight

LazSlate

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To those who upgraded to bigger tires do you notice any difference on acceleration and braking? I know MPG will be affected in the city with stop and gos.
Looking at the stock tire on the Timberline its about 40lbs and upgrades to bigger tires avg 60-73 lbs. The 2 tires I am looking at are 63lbs and 73lbs.
 

cptbligh

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Yes! I have LT285/60/R20 Open Country Mud Terrains on my Limited and 9th and 10th gear are basically useless now and I generally drive in sport/tow mode at lower speeds to have any torque available. Maybe the Timberline is a little better if the rear gear is shorter.

Nitto Terra Grappler G2s and BFG KO2s are available in P rating in larger sizes I believe so they are lighter than LTs. I'd probably go with them if I had a choice to do over.
 

rd618

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Yes! I have LT285/60/R20 Open Country Mud Terrains on my Limited and 9th and 10th gear are basically useless now and I generally drive in sport/tow mode at lower speeds to have any torque available. Maybe the Timberline is a little better if the rear gear is shorter.

Nitto Terra Grappler G2s and BFG KO2s are available in P rating in larger sizes I believe so they are lighter than LTs. I'd probably go with them if I had a choice to do over.

I don’t follow this?
285/60-20 is marginally larger than stock wheels. (285/45-22 on mine). It’s roughly 1.5” larger diameter. With the same width.
I drive like normal and have plenty of power. I don’t see how a 4-5” tire circumference will cause you to require driving in tow/haul in lower gears or making 9/10 useless.
 

cptbligh

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I don’t follow this?
285/60-20 is marginally larger than stock wheels. (285/45-22 on mine). It’s roughly 1.5” larger diameter. With the same width.
I drive like normal and have plenty of power. I don’t see how a 4-5” tire circumference will cause you to require driving in tow/haul in lower gears or making 9/10 useless.

285/60 (33.5") is ~5% larger diameter than the stock 275/55/20 or your 285/45/22(32"). Combine that with the stock Hankooks only weighing 40 lbs vs the MTs I have at 69 lbs. I can't maintain 60mph on level ground without going into boost in 9th gear.

The Limited has a tall 3.31 gear ratio. I think the Timberlines have 3.73s so that would help.
 
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LazSlate

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285/60 (33.5") is ~5% larger diameter than the stock 275/55/20 or your 285/45/22(32"). Combine that with the stock Hankooks only weighing 40 lbs vs the MTs I have at 69 lbs. I can't maintain 60mph on level ground without going into boost in 9th gear.

The Limited has a tall 3.31 gear ratio. I think the Timberlines have 3.73s so that would help.

Wow that is strange. Never heard this from tires that size on the standard epys. Do you have the tires aired up to the upper levels? Any aftermarket roof racks or such?
 

cptbligh

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Wow that is strange. Never heard this from tires that size on the standard epys. Do you have the tires aired up to the upper levels? Any aftermarket roof racks or such?
In my case it's more the weight than the size of the tires I believe. I removed my roof rack to fit in my garage but I do have a leveling kit. I have AT3s on my F150 and it's not near as big of an issue.
 

LokiWolf

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Going to larger, heavier, more aggressive tires will ALWAYS negatively affect power and MPG. It is just physics. More unsprung weight, and rolling resistance. Takes more energy to get moving and stay moving.

Also the Timberline and a Limited with 4x4 Max Tow are both 3.73. Actually it looks like according to the 2022 Tow guide, if you have the ELSD equipped it is the 3.73. So really has nothing to do with trim, and more about equipped options.
 

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I have a '21 FX4 that came with Michelin Primacy 275x65x18 all terrains but P rated. Went with 275x70x18 BFG KO2's that are 10 ply E rated that weigh 57 lbs ea. Bought these for minor offroading and towing our almost 8K pound camper. About 1 mpg loss in fuel mileage and some decrease in braking but not bad at all. Still can get up to 22 mpg hwy and 17 to 18 mpg out in the country town where I live. The FX4 has the max tow package with 3.73 gearing ..trailer backup assist and brake controller. Very pleased with these tires and run 42 psi cold for daily use and air them up to 60 psi when towing. Have 8K miles on them and no signs of wear.

IMG_6209.JPG
 

JohnSC

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Going to larger, heavier, more aggressive tires will ALWAYS negatively affect power and MPG. It is just physics. More unsprung weight, and rolling resistance. Takes more energy to get moving and stay moving.

Also the Timberline and a Limited with 4x4 Max Tow are both 3.73. Actually it looks like according to the 2022 Tow guide, if you have the ELSD equipped it is the 3.73. So really has nothing to do with trim, and more about equipped options.
This seems wrong at first glance, it seems like the tire is rolling and should not need a lot to keep that happening. Until you consider that when the car is running at 60 MPH, the outside tread of the tire is going from zero when it is in contact with the road to 120 MPH at the top of the tire, to zero again when it reaches the bottom again. Hundreds of times per minute. That is a lot of mass to accelerate and slow that often.
 
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LazSlate

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This seems wrong at first glance, it seems like the tire is rolling and should not need a lot to keep that happening. Until you consider that when the car is running at 60 MPH, the outside tread of the tire is going from zero when it is in contact with the road to 120 MPH at the top of the tire, to zero again when it reaches the bottom again. Hundreds of times per minute. That is a lot of mass to accelerate and slow that often.


Thats not quite how it works. The tire is not going 120 MPH and it's not stopping and starting from zero?

The 285/60/20 has a circumference of 105"
At 60 MPH this equates to the tire rotating at 602 RPM
To get the surface speed in minutes you multiply: 105" x 602 rpm = 63,210 inches per minute
Divide it by the inches in a mile 63,360
63,210 / 63,360 = 0.9976 this is the surface speed in miles per minute

Multiply by 60 to get the MPH and its of course 60 since it has to be at least the speed of the vehicle.
But its rotating a constant velocity so it never changes speed. This is why larger tires like on a semi spin slower because the larger the diameter the higher the surface speed for a given RPM.

I do endless calculations like this for my job all the time.
 
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