Maybe it's just the 4 cyl.
I'm running 31x10.5x15 on mine . It's a heavier crew cab 3.5 5 cyl and mine runs fine and doesn't down shift on Highway at all. Actually impressed with how many low rpms it will hold.

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Yeah, that setup is ok with a 5cyl, but works a 4cyl pretty hard.

Now that the truck is lifted, the stock size will look small, unless you put the suspension back to stock height.


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I have a 2005 Colorado Z71 3.5L crew cab running 31x10.5x15 on it with and it does good. I'm running stock as far as suspension. My guess is the tires may be a little too much for that motor. I'm assuming your getting pretty terrible fuel mileage as well.

2010 GMC Canyon

2.9-liter in-line 4
185 horsepower @ 5600 rpm
190 lb.-ft. of torque @ 2800 rpm
EPA city/highway fuel economy: 18/25 (2WD), 18/24 (4WD, manual), 17/23 (4WD, automatic)

3.7-liter in-line 5
242 horsepower @ 5600 rpm
242 lb.-ft. of torque @ 4600 rpm
EPA city/highway fuel economy: 17/23 (2WD), 16/22 (4WD), 17/24 (2WD, Crew Cab), 16/21 (4WD, Crew Cab)

 

It does seem to work the small motor some what , and milage varies from 17-20.5 on the hyway . I am leaning towards going back to a 16 inch wheel and a smaller tire.

 

Hi Guys I am a new member and recently purchased a 2010 Gmc Canyon 4x4 Regular cab with the 4 cylinder 4 speed auto with 3.73 gears. It has a suspension max front and rear suspension lift installed on it and 265/70r17 tires . The truck runs ok on the hyway but does down shift a lot with the larger tires on it ........ The stock size that it came with is 235/75r16 , the stock wheel and tire setup did not come with the truck, how do these trucks run with the stock setup?


thanks

A lot better. Your tire is almost 10% larger than stock. (I have same size on my Z85).

I can't drive around town in O.D., When it shifts around 45mph, it's lugging the motor more than I prefer, so I keep it shifted to 3rd in town.

Guys with 31's who say it runs fine usually have the Z71, and the 31" is stock size. Your 31.7" is a long way from 29". The Z85 tune is the problem....the shifting points and fuel curve data is out of wack. Or if they have a Z85, the 31" tire is only half of the increase in size that your truck has.

 

I'm a 4x4 3.5 z85 and I didn't have any problems with 31's. It's probably the smaller engine.

 

I got a 4 cylinder 2.8 with 31's and it downshifts all the time on the highway... any little hill and if it is real windy...

 

Stock on 2010 = 29.88"
31's = 3.8% larger
265/70-17 = 5.8" larger actually (not as much as previous model years)

Pre 2009 models (15" wheel)
Stock = 28.88
31's = 7.4% larger
265/70-17 = 9.5% larger

It's all about the tune of the computer. It's tuned to deliver fuel at specific RPM, and that is altered. The gear ratio is higher with taller tires, it shifts too soon, computer delivers fuel inaccurately.

You could look into having your computer tuned for the larger tire. Even just to compensate for the taller tire will be helpful, but if you find somebody to get into the computer it might be worth considering.

Keep in mind, if you have a warranty, you COULD void warranty with a tune. It depends on the person do the repair work to notice the tune, and report it to the warranty company. If they don't report it, no problems.....

 

Ok that makes sense ... I'm thinking of going to a size of 245/75r16 instead of 265/70r17 what do you guys think of changing to that size?

 

If you mean your truck has SuspensionMaxx shackles in the rear you may want to lower it down a little bit.
There is a suspension max company out there too.

The tire you listed is about 1/2" taller than stock. If the rear is in the tallest position (2"), it might look tall for the stock sized tire. It's not necessary, but at least with adjustable shackles you have the option.

Your next dilemma may be wheel choice, finding something that fits nice. A stock Z71 wheel would be good, 7.5" wide. Or a wheel between 7.5" and 8" with a backspace around 5" is likely what you'll be after. It will give you just a little poke, shouldn't rub and give it a decent stance. All personal preference though.
That's all been discussed thousands of times though. You can find all kinds of info on that if you choose to make this change.

Your truck will be happier and probably more fun to drive with a smaller tire...but I don't think it will make a ton of difference. Some, possibly noticeable but I wouldn't go through the expense of $1000 (rims/tires) just to make it more fuel efficient.

 

That's true , I would have to buy wheels and tires to gain a couple mpg .... It would take a while to gain that cost back .

 

btt

 

Wish I saw this thread before I got my tired. Went from the stock 215/70/16 to a 265/65/17. Hwy went from 24 to 19.5 mpg. I've got all the bolt ons and tune so my question is, would entering the correct tire size alter the shift points and fuel ration or would I have to get back in and toggle with everything to get the maximum benefit?

Edit: 2012 z85 crew cab 2.9L with 3.73 gears

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A tune to correct for tire size 'should' remap the shift points.

The tires are way big, it won't be as good as stock. But it should improve. You have a small engine and huge tire size increase. Not much you can really do, but hope for the best with your second tune.

 

I went from 235/70/15s to my current 31/10.5/15s I honestly see better hw than I did with the older setup. With my 235s I got a consistent 280 Mi per tank. I just got over 330 with my 31s.

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I'm at 330 right now was getting 400 a tank


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I bought the same tire size just ordered some 17x8 also just wanted to know if I would be able put them on with no problem, with the stock suspension it's a 2007 Colorado 4x4 it's got the front bumper hooks dnt know if it's the z71 though.