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Discussion Starter #1
How much of a power loss did you guys with 285's notice with stock gears and a v6? I can't decide. Any info would help. Like rpm's compared with 285's to stock.
Thanks
 

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I am currently on 275 75 tires and milage is right at 300 a tank. Doubt its going to change that much more with 285's. Think of it as adding on about 12 lbs to your current weight load at most
 

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obex26 said:
I am currently on 275 75 tires and milage is right at 300 a tank. Doubt its going to change that much more with 285's. Think of it as adding on about 12 lbs to your current weight load at most
It's more complicated than just adding the additional weight of the tires. It takes the engine a lot more effort to get those heavier tires rolling. Even after correcting for the tread length difference, he could notice a 2-3 mpg loss on top of that.
 

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Discussion Starter #4
I know I will notice a mileage decrease but I am pretty much worried about the get up and go of it.
 

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You will notice it. It changes your shift points and makes 5th gear a little tougher to use. The speedometer is off about 3 or so mph for me. I went from the TRD 265/70 on 16x7 setup to 285s on 16x8.

I plan on regearing at some point to 4.56
 

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Hey, Aaron, how's Germany? How's the wife holding up in Iraq?

As for your question, the power loss will depend on the gears you have. I had 265/75s with 3.58s gears, 5-spd, and 2.7L. That was really doggish compared to where I'm at now with 4.88s and 33s.

Do you know when you are supposed to come back?

Take care,
 

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Hey so do ypu think Iwill be ok if I dont regear with a s/c? Also where did you get your wheels I like them?
 

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yeah she comes back in one month but I fly out to the states next week where we will vacation. I cannot stand this deployment crap!!! I have a v6 tacoma with 4.10 gears and I just bought a s/c. You think this would be alright with 285's. I just can't justify the whole regearing thing.
 

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By the way I see your board name but what is your name I dont recgonize you by your board name. Oh and I will be home in Utah in 12 months
 

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Mudferret, You are going to notice more of a loss in "performance" with the added weight of your toolbox and bumpers then you ever will with a change of 10 mm in revolution surface. The added physical weight of a human body or objects will decrease more of your performance then a height difference of 10 mm on your tires. If you were to take a person who weighs 140 lbs and place them in a vehicle which has a tire combo of 285 70 16 with stock wheels. And then take a person who weighs 180 lbs and place them in an identical vehicle with no changes other then the tire size of 275 70 16. I promise you the first combo wil have a better response to performance even with the larger tire. The loss of difference will always be an issue of weight versus size. Yes you could put the same size person in both vehicles and yes the second tire option will have an improved performance but then it will come down to one issue and that is the difference in weight of the tires. This will not affect your milege in a 2-3 per gallon stance. 10 mm of tire are going to reduce the distance of revolution somewhere near 43 feet shorter in the completion of 1 mile.

Say for example you have roughly what 6440 feet to equal a mile if you subtract the estimated 43 feet the mile has been reduced by speedometer calibration for the larger tire size it takes 6397 feet to equal the same mile it previously did with the smaller tire. So 6397 x 50 miles you are now covering the distance of 319850 feet which is equal to the original distance of 322000 feet. For a loss of 2150 feet of calibration.

So if 322000 feet equals 50 miles and you divide that by 18 miles to the gallon you are getting 17888 feet per mile. If you take take the estimate of 319850 feet which also equals 50 miles and divide it by 18 you now have 17770 feet. A difference of 118 feet per mile your overall loss is at most 9/10ths of a mile in per gallon.

Matt your shift points do not change unless of course you have modified your computer. The computer gets its speed reading from the sensor cable which is at the end of the transmission not the tires. :p
 

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I think the weight is what I pointed out, no? I pointed out the tread length diff, a subject I'm quite familiar with, because a lot of people tend to NOT correct for that.

The tread length diff between the stock 265/70/16 and a 265/75/16 is on the order of ~3% depending on tire brand, since the sizes aren't always what they "should" be.

Rotational mass plays a tremendous role in MPG... I'd pull out the physics BS but I'm much too lazy.

Addendum: Tread length only creates the appearance of less mpg, everything else being equal this is completely separate from rotational mass.


obex26 said:
Mudferret, You are going to notice more of a loss in "performance" with the added weight of your toolbox and bumpers then you ever will with a change of 10 mm in revolution surface. The added physical weight of a human body or objects will decrease more of your performance then a height difference of 10 mm on your tires. If you were to take a person who weighs 140 lbs and place them in a vehicle which has a tire combo of 285 70 16 with stock wheels. And then take a person who weighs 180 lbs and place them in an identical vehicle with no changes other then the tire size of 275 70 16. I promise you the first combo wil have a better response to performance even with the larger tire. The loss of difference will always be an issue of weight versus size. Yes you could put the same size person in both vehicles and yes the second tire option will have an improved performance but then it will come down to one issue and that is the difference in weight of the tires. This will not affect your milege in a 2-3 per gallon stance. 10 mm of tire are going to reduce the distance of revolution somewhere near 43 feet shorter in the completion of 1 mile.

Say for example you have roughly what 6440 feet to equal a mile if you subtract the estimated 43 feet the mile has been reduced by speedometer calibration for the larger tire size it takes 6397 feet to equal the same mile it previously did with the smaller tire. So 6397 x 50 miles you are now covering the distance of 319850 feet which is equal to the original distance of 322000 feet. For a loss of 2150 feet of calibration.

So if 322000 feet equals 50 miles and you divide that by 18 miles to the gallon you are getting 17888 feet per mile. If you take take the estimate of 319850 feet which also equals 50 miles and divide it by 18 you now have 17770 feet. A difference of 118 feet per mile your overall loss is at most 9/10ths of a mile in per gallon.

Matt your shift points do not change unless of course you have modified your computer. The computer gets its speed reading from the sensor cable which is at the end of the transmission not the tires. :p
 

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Also, it appears he has the stock 265/70/16's on there (30.6" in a perfect world) compared to the 285/75/16's he mentioned (32.8" in a perfect world). So if we use the formula for percent difference, it could appear that he's getting less mpg than he actually is:

([30.6-32.8]/30.6)*100
=-7.2% error in his speedo since diameter and tread length are proportional

obex26 said:
Mudferret, You are going to notice more of a loss in "performance" with the added weight of your toolbox and bumpers then you ever will with a change of 10 mm in revolution surface. The added physical weight of a human body or objects will decrease more of your performance then a height difference of 10 mm on your tires. If you were to take a person who weighs 140 lbs and place them in a vehicle which has a tire combo of 285 70 16 with stock wheels. And then take a person who weighs 180 lbs and place them in an identical vehicle with no changes other then the tire size of 275 70 16. I promise you the first combo wil have a better response to performance even with the larger tire. The loss of difference will always be an issue of weight versus size. Yes you could put the same size person in both vehicles and yes the second tire option will have an improved performance but then it will come down to one issue and that is the difference in weight of the tires. This will not affect your milege in a 2-3 per gallon stance. 10 mm of tire are going to reduce the distance of revolution somewhere near 43 feet shorter in the completion of 1 mile.

Say for example you have roughly what 6440 feet to equal a mile if you subtract the estimated 43 feet the mile has been reduced by speedometer calibration for the larger tire size it takes 6397 feet to equal the same mile it previously did with the smaller tire. So 6397 x 50 miles you are now covering the distance of 319850 feet which is equal to the original distance of 322000 feet. For a loss of 2150 feet of calibration.

So if 322000 feet equals 50 miles and you divide that by 18 miles to the gallon you are getting 17888 feet per mile. If you take take the estimate of 319850 feet which also equals 50 miles and divide it by 18 you now have 17770 feet. A difference of 118 feet per mile your overall loss is at most 9/10ths of a mile in per gallon.

Matt your shift points do not change unless of course you have modified your computer. The computer gets its speed reading from the sensor cable which is at the end of the transmission not the tires. :p
 

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Sounds alright, especially with a supercharger. If you want better offroad performance, however, you might want to step up to 4.56s.
 

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I'm not buying it that there is not that much of a loss of power with 285's. Maybe if you are hammering it and at full throttle. I would hate to think that someone would go and drop down $1000-$1500 on new tires and wheels to find that--Oh there is a big difference in the way the truck performs. The larger diameter tire in addition to having a wider tire increasing rolling mass has to decrease performance. I have to believe that Toyota provides a truck with the optimum combination of power and fuel economy, and when you change from stock, it's not usually for the better. There just seems to be a lot of people, including me, that are going with 4.56 or 4.88 gears to get back a little of what was lost with going to larger tires 33 inches+. A big consideration I think if you are to be happy with your daily driver for a period of time. It only took me one week to be tired of not having the pick up without giving the truck a lot of gas pedal and a loss of 4-5 miles per gallon.
 

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You replied to the wrong person, I said nothing of that sort.

Toyota4ever said:
I'm not buying it that there is not that much of a loss of power with 285's. Maybe if you are hammering it and at full throttle. I would hate to think that someone would go and drop down $1000-$1500 on new tires and wheels to find that--Oh there is a big difference in the way the truck performs. The larger diameter tire in addition to having a wider tire increasing rolling mass has to decrease performance. I have to believe that Toyota provides a truck with the optimum combination of power and fuel economy, and when you change from stock, it's not usually for the better. There just seems to be a lot of people, including me, that are going with 4.56 or 4.88 gears to get back a little of what was lost with going to larger tires 33 inches+. A big consideration I think if you are to be happy with your daily driver for a period of time. It only took me one week to be tired of not having the pick up without giving the truck a lot of gas pedal and a loss of 4-5 miles per gallon.
 

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Toyota4ever said:
I'm not buying it that there is not that much of a loss of power with 285's. Maybe if you are hammering it and at full throttle. I would hate to think that someone would go and drop down $1000-$1500 on new tires and wheels to find that--Oh there is a big difference in the way the truck performs. The larger diameter tire in addition to having a wider tire increasing rolling mass has to decrease performance. I have to believe that Toyota provides a truck with the optimum combination of power and fuel economy, and when you change from stock, it's not usually for the better. There just seems to be a lot of people, including me, that are going with 4.56 or 4.88 gears to get back a little of what was lost with going to larger tires 33 inches+. A big consideration I think if you are to be happy with your daily driver for a period of time. It only took me one week to be tired of not having the pick up without giving the truck a lot of gas pedal and a loss of 4-5 miles per gallon.

I just went from 265/75R16 to 285/75R16's last week. There is some loss of power, and my gas mileage is not stellar. I do have to down shift to 4th, when 5th gear would have pulled just fined with the 265/75R16's. I'm looking to get some 4.56's in the next month or two.
 

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Toyota4x4man said:
How much of a power loss did you guys with 285's notice with stock gears and a v6? I can't decide. Any info would help. Like rpm's compared with 285's to stock.
Thanks
a lot will depend on the terrain you drive. At sea level and on flat ground you won't notice it that much. But, get on hills or towing/hauling and you'll really wonder where the power went.

With the taller tires the engine has to work that much harder to turn them and that takes more gas. After regearing I found myself using a lot less pedal to get going than I used to.

If you don't want to mess with the 'regearing thing' then keep the 265s or get used to less power and mileage.
 

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troyota said:
man you will love the s/c. what a power difference!

sc? and by the way what does IMO mean???
 
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