what size tire will fit?

[hpracing10]

On my 2003 silverado halfton Z71 I currently am running 265/75R16 size tires. Knowing nothing about tire sizes, I want to go up like one size, what size would that be? Just want to give the truck a little "beefier" look.

Also, WILL a bigger size tire even fit? I don't have a lift or anything like that and I don't plan on it, just wanted a little bigger tire than what I have on now, which I believe is the stock size.

One more thing, will a bigger tire affect my MPH or anything like that? Didn't know if a larger diameter tire will make the speedometer read any differently. Thanks for your replies.

 

[mrsilv04]

You might try the discussion board at gm-trucks.com

Someone there should know exactly what fits, and what doesn't.

I believe your next size up would be a 285/75-16. I'm sure I've seen it on GMT800 1/2 ton 4x4's. It should fit without modification.

Yes, it will throw off your speedometer. Yes, you are running a stock size right now.

Unless you're willing to modify the truck, I don't think you'll be able to any larger than that.

 

[Fazzone]

You should be able to put 285's on, but you might need to do a little trimming of the plastic on the bottom of the bumper. My cousin put those on his '03 2500 and had to. Still rubbed a little at first, but couldn't figure out where. After about 1000 miles, it went away. Just be warned, you will probably get worse gas mileage with the bigger tires. I went up a tire size and lost about 1 mpg(yes the speedometer was recalibrated after).

 

[chad8]

try this chart below
if you go to a 285 you should probably drop your profile to a 65

http://www.tirerack.com/upgrade_garage/Garage.jsp

 

[hpracing10]

chad8, what do you mean by profile? like the width of the tire or the hieght of the sidewall or what?

 

[mrsilv04]

A 285/65 as Chad8 suggested, is going the wrong way. You'll end up with a smaller diameter tire than you have now, with a shorter sidewall. Not sure why he thought that was a good idea.

Here's a breakdown

265/75 - Overall diameter = 31.64", Sidewall height = 7.82" Width = 10.43"

285/75 - OD = 32.83", SH = 8.41", W = 11.22"

285/65 - OD = 30.58" (smaller than what you have now), SH = 7.29" (shorter than what you have now), W = 11.22"


The 285/65 will not accomplish what you're looking for.

 

[hpracing10]

Ok, thanks for the crash course on tire sizing. I still haven't decided what to do yet. A larger tire will effect my towing and acceleration so I'm not sure if I want that yet or not but I do like the looks of a bigger tire on trucks.

off subject, mrsilv04, how does your silverado 5.3 like that pennzoil platinum 5w-30? Everytime I change oil i stare at the PP bottle on the shelf for a long time before grabbing the Mobil 1.

 

[mpvue]

Originally Posted By: hpracing10
Ok, thanks for the crash course on tire sizing. I still haven't decided what to do yet. A larger tire will effect my towing and acceleration so I'm not sure if I want that yet or not but I do like the looks of a bigger tire on trucks.


few things you need to know about tire sizing on trucks:
the size you have now is the standard passenger car sizing system. the 1st number is the WIDTH in millimeters (you can convert it to inches by dividing it by 25.4). the '75' in the size is the SIDEWALL RATIO, meaning the sidewall is 75% of the width. the '16' is the rim diameter.
if you want a taller tire, I would recommend you look into a LT (lght truck) tire. they are sized in inches. you could probably put a 33x10.5 on there, but you should check w/ a good truck tire shop or tirerack.com

 

[mrsilv04]

Originally Posted By: hpracing10
off subject, mrsilv04, how does your silverado 5.3 like that pennzoil platinum 5w-30? Everytime I change oil i stare at the PP bottle on the shelf for a long time before grabbing the Mobil 1.


I'm using it in two GM trucks, a 2000 Sierra 5.3 and my 2004 Silverado 5.3. The Sierra has 75,000 miles, and the Silverado has 55,000 miles.

In the Sierra, I use 10w-30, since it has a little bit of piston slap. I use 5w-30 in my Silverado, no piston slap.

For filters, I use NAPA Gold/Wix (or an AC Delco in a pinch).

I run it for 5,000 miles in both vehicles, which is usually when the OLM lights up anyway. Both trucks are used as trucks, and pull trailers (and travel trailers) regularly.

It works well for me, I can't see using anything else. After seeing how well it performs here, it was an easy choice.

 

[hpracing10]

I might have to try PP for my next oil change. Right now I'm using Mobil 1 TDT 5w-40. My truck has high miles and recently I have seen a very slight drop in oil pressure at hot idle, so that is why I am using a 5w-40 instead of a 5w-30. Does PP come in a 5w-40? If so, I would be interested in using it.