What size engine? What rear end gearing? Auto or standard?

 

31's are stock on a Z71.You can move up a little bit. 265/75-16 or 265-70-17. These tire choices are about an inch taller than stock. If you drive a Z85 the options listed about about 10% larger and fuel cost will suck with the choices I listed. Ask me how I know. I drive a Z85 with 265/75-16 and return around 15mph city. I also have the 3.7l, not a 4-cylinder.
33's could be an option (not a good one) and forget about 35's (they aren't going to fit).
I can't quite understand why you said you want 35" tires after complaining about the cost of fuel anyway. It's definitely not going to get any better unless you have the computer retuned.

The options I listed won't rub as long as you get the proper wheel backspace.


Moderators - this thread belongs in the 1st gen section.

 

Hating the cost of gas and wanting bigger tires doesn't really go together. I run 33s and would never think of going to 35s, it's just too much I think, at least for me.

Some good 31s would be nice. Falkin Wildpeaks are personally going to be my next tire choice, but I currently have Wrangler Duratracs.

 

I wasn't complaining about the gas. I was saying I don't want to go to big where I end up spending so much on gas I end up hating driving the truck cause I went to big on tires. I love my 31s and the gas is fine with them on but with the new fenders they need to go up a little bit in size. It's a 5 cyldener, automatic and I'm pretty sure it's a 2.9L, I would double check but I'm not with my truck at the moment. The reason I said 33-35 is because I was looking at some where in the area so you guys knew what size's I was looking at. 35 is pushing it for me in my opinion but I was wanting to see if anybody has already done it or has bigger tires then what I have and how it is with tires that size

 

You had this in the 2015 section. Moved to first gen section.

 

It's a 3.5 litre. 35s are a definite no without Atleast 4.56 gears I'd say. 33s you will notice a power loss if you're on lower than 4.10s

 

How much of a loss in power you think it would lose? Cause the 31s it doesn't seem to have an struggle at all. I would like to at least try to get 33s on there but if there is a huge power loss I would rather just probably stick with the 31s. What do you think?

 

33s are OK. I find It tough to hold overdrive on hills though. I have 3.73 rear end. From 31s to 33s I definitely noticed a drop in power but not so much that it's undrivable. I wouldn't even try 35s on mine without regearing though

 

Yeah I'll probably try the 33s then cause I'm not trying to go do something stupid where it's pointless in driving it. What kind of 33s do you have? And is your truck lifted or stock?

 

I'm running 33x12.5r15 Goodyear Duratracs. I'm cranked 3 inches and have 2 inch shackles. Sway bar delete and lower bumper valence delete to avoid rubbing issues.

4.75 backspace

 

You need to know the gear ratio. Your question about 'how much loss of power" can't be answered without knowing the drivetrain.

If you have a Z85 with high gears and a Z85 tune, running 33's will make you want a new truck because power is gone.

Having 31's now is not useful info to us. For all we know, it's stock.

What is the stock tire size please. The true and accurate information is on your driver side door jamb (manufacturer sticker).

Also, open the glove box and read the alpha-numeric codes. It will identify Z85 or Z71 on the silver sticker.
Refer to this post http://www.355nation.net/forum/engi.../engines-performance-tech-questions/150665-4-cylinder-2wd-safe.html#post3837489 to determine which gear ratio you have. the codes are also on the silver sticker.

I dropped from 20mpg to 15mpg in my 3.7l engine, 3.73 gears rolling on 31.7" tires.

 

For another reference to go along with the post above:

I'm a z71 with 3.73 gears and a 3 inch lift. On 31s I was getting around 21Mpg (I'm also tuned 50/50 and have a modified intake and straight exhaust no cats). Now on 33s I get around 17mpg. Both of those are highway, I don't care about my city mileage because I know it's crap. I drive like an idiot because I like to make noise.

But yes before going on definitely let us know what gear ratio you have and what your stock tire size is. If you are rolling on 3.42s you're going to have a bad time on 33s.

 

Weird, because I have 33s with 3.73 gears and I'm lifted 6.25" front and 4" rear, getting about 21-23 mpg on the highway. I am not tuned yet either. I only really make noise in the city though lol.

 

I did my conversion from lp100k to mpg wrong. I'm getting 23mpg on my 33s

 

I don't really go over 115km/h too much. Unless I'm on the stretch from Grand Rapids to Ponton. No cops for 175km and if you see one they don't give a fuck. I flew past one doing 160km/h one time, boy did I almost shit my pants when I realized it was a cop coming the other way.

*EDIT* My rpms are usually around 2000-2200 on the highway.

 

Getting about 15mpg at this very moment with my trailer on lol.

 

Unless the computer has been calibrated for tire size, RPM/Speed are estimates.

Remember, speedometer is off by same percentage as tire increase above stock (unless tuned).

I barely break 20/21 with 31.7" tires with my factory Z85 PCM tune. That is with my Ultragauge configured for the size tire to alter the display readings (not actually tuned).

 

It has been tuned for the tire size

 

Okay so I have seriously tore my truck apart looking through everything in my glove box, owners manual, you name it and I couldn't find anything saying if it was a z71 or z85 and I also couldn't find the gear ratio. I really appreciate you guys trying to help me out but I'm not sure where else to look?

 

Open the glove box. There is a silver sticker on the actual glovebox door (inside).

The glove box is located about knee level (with passenger seated in seat) in front of the passenger seat. No need to disassemble your entire truck.

This guy is going through the same thing as you.
He posted a pic of the sticker (RPO Codes).
http://www.355nation.net/forum/off-topic/150881-gears-more.html

 

I know, I found the sticker. It was a little faded that's why I looked over it. Okay I'm posting a picture of it so you guys can see and hopefully be able to help me out. Let me know if I need to take a better one.

 

Z85 suspension and 3.73 gears (GT4)

 

So u have a z85. GT4 is 3.73. And no g80.

Edit: looks like someone beat me to it.

 

Here's the link to the RPO codes if you want to know more.

http://www.355nation.net/forum/how-.../how-tutorials-reviews-service-bulletins/1315-colorado-rpo-codes-full-list.html

 

So with that being said would I be able to run 33s on my truck or would it not be a good idea. I also plan on adding in a performance chip and a cold air intake for a little more power. I don't know if that helps or not but figured I would add that in

 

"Performance" chips are a waste of money. Do some research on here and you'll find they dont do anything. I put a jet performormance chip on a dodge ram i had and it didnt do shit. Go with a custom mail order tune. I just got one and it makes a world of difference. Definitely do some research on here though.

 

http://www.355nation.net/forum/carid-com/124450-superchips-really-super.html

:lol:

 

33x10.5 tires with the right wheel (not stock) and more than likely at least some rubbing. I really have no clue about how much and when/where it will rub. I would expect it to be worse if you hit bumps and steer at the same time.
Driving it will suck though.

I'm sticking to what I said in post #2.

For what it's worth, I wish I had 31's.