Biggest Tires on A Stock Chev TrailBoss (W/Without A Lift)

The TrailBoss is an excellent off-the-floor type truck that can handle most tough tracks with few modifications. Those TrailBoss wheel arches are just begging for a bigger tire to fill them out properly allowing you to take on those tough tracks with more confidence. So, the question that many TrailBoss owners want to know is, what is the max tire size you can squeeze on a stock Chevy TrailBoss with stock rims?

The maximum tire size that a Chev TrailBoss can accommodate on a stock suspension is up to a large 32-inch tire. Fitting a 33-inch tire or bigger requires a suspension lift, 1.5” spacer kit combined with a negative offset rim/wheel.

Why GM decided to release the TrailBoss with an insignificant 32-inch tire baffles me, especially since other GM models that are less geared for off-roading are released with 33 inches. Be that as it may, the other problem is the TrailBoss wheel arches are known to be rather narrow which limits you somewhat when fitting bigger tires.

Let’s see what is required to make a 33-inch tire fit on a TrailBoss.

Biggest Tires on A Stock Chev TrailBoss (W/Without A Lift)

Fitting Spacers & Lift with 33” tires on your TrailBoss

In stock form, the TrailBoss comes wrapped in 32×10 tires which is, in many owners’ opinions, not the best size for this big truck. So, when upgrading from a 32×10 to a 33×12 on stock rims you will experience a massive amount of scrubbing inside those wheel wells. You will have to do quite a bit of trim on the plastic fenders which isn’t ideal if you plan on selling the truck later down the line. Any tire bigger than the factory 32-inch versions is going to require a lift kit or at least a spacer kit up front.

The perfect setup would be a small 1.5” spacer or lift kit combined with a negative offset rim/wheel to make those 33 inches fit and function properly offroad without any scrubbing offroad or at full lock.

Bigger Than 33-Inches on A Lift

If, for example, you run something bigger than a 33-inch and only opt for a 1.5-inch spacer while running factory rims/wheels you could get away with about a 295/70/18 which is the equivalent to a 34.3-inch tire. In this instance, you will need to trim the mud flaps hidden inside the wheel well. You will also need to remove the bracket that is tucked away behind the fender liner.

The upside with the spacers is the amount of stability you get on the TrailBoss. The truck’s handling is greatly improved with less body roll giving it a more planted feel when cornering.

33 vs 35-inch tires (Size, Weight, Height)

Fender Trimming

What needs to be trimmed when fitting oversized tires on your TrailBoss? Well, there is a bracket that is located directly behind the mudflap that needs to be removed. You also need to trim a bit off from the inside and systematically trim your way outward until the rub is eliminated. Do it in stages, only trimming little bits at a time to avoid cutting away too much and leaving unsightly spaces/gaps in your wheel wells.

If you drive a Silverado your job is a bit easier. There is no need for drilling or cutting too much and can get away with a simple zip-tie. Tie the hole in the fender liner (from discarded hardware) to the hole that the bracket used to be mounted to. Job done!

Fitting Aftermarket Rims/Wheels to your TrailBoss

The stock tires are 32-inches, and 10-inches wide which is rather puny for such a butch truck. It doesn’t do the truck justice to be cruising around with such tiny wheels. The problem with the TrailBoss is that it has a very narrow wheel arch which makes it rather difficult to simply upgrade to a 33-inch tire without any additional mods.

Here is where the aftermarket rims/wheels come in. Any rim/wheel with a more negative offset will push those tires out more, thus creating more space in the back of the tire to clear the UCA (Upper Control Arms) as well as the inside of the narrow wheel wells. The wheels will definitely stick out a bit, but it will negate the need to cut up your wheel wells and do any trimming on the arch flares.

Let’s say you opt for a 33-inch by a 12.5 then you’ll be hitting a sweet spot between looks or aesthetics and improved offroad capability. That’s exactly what you want! You don’t want to have to throw tens of thousands at the truck just to fit bigger tires.

35s vs 315 tires on 17-inch rims (Size/Weight/Height)

WATCH – 35s on a Stock Trailboss (VIDEO)

User Experience & Feedback

User 1

I’ve got 295/70R18 Falken Wildpeak AT3W tires on my 18-inch Trail Boss wheels. Just a tiny bit of rub on the mud flap occasionally when reversing with steering near full lock. I don’t have any lift or leveling kit, just factory Trail Boss suspension.

User 2

I put Toyo 195/70’s on mine. So, 34X11.5 roughly. I had to remove the mud flaps when I added Bushwacker fender flares. When I added the tires I had to remove the mudflap brackets and add 2″ wheel offsets. When that was done I had no tire rub. Before the spacers It rubbed bad. Hell of a racket. I’ve read on the GM forums that you could put 195/70 without any rubbing. Anyone who says that is wrong.

User 3

I run 295/70 yokahoma x-at, on stock 18. No rub, no spacers. Places them right at the outside edge of the fender. Spacers would put them outside and look great IMO. With spacers, the 295/65 will fit.

Biggest tire you can fit on a Stock Silverado 1500 – Fitment Guide

If you’re interested to know the biggest tire size you can fit on your Silverado 1500 running on stock suspension, then you’ve come to the right place. A big tire upgrade is usually one of the first and most popular modifications to off-road trucks since it’s the easiest way to get a more aggressive look, increase the ride height, and improve traction and capability both on and off-road. So what are your big tire options on the 3rd and 4th Generation Silverado?

The biggest tire you can fit on a 3rd and 4th generation Chev Silverado 1500 running factory stock suspension and rims are 33.5”. The factory standard tires are 31.6’ in the form of 265/65/R18 and 33” in the form of 275/60/R20, so an extra inch or so is possible.

If you are not prepared to do trimming and cutting and you are running stock suspension then you’ll be limited to a maximum of 33.5-inch tires, however, this is not recommended. The good news is, you’re not completely limited and there are many other options you can try.

This article will cover what exactly is required to make the biggest 33-inch tires fit, as well as some of the most popular tire and suspension combinations on a Chevy Silverado 1500 that absolutely works.

Read the full article here



The TrailBoss is an excellent platform if you want a truck that’s ready to hit the trails. A Simple big-tire upgrade will allow you to tackle those tracks with confidence without having to spend tens of thousands on the truck to get it capable and trail-ready. Follow the above-mentioned guidelines before fitting 33-inch or 35-inch tires and you should be ready to smash trails you never thought possible with your humble but very capable TrailBoss!

Jade C.

4-Wheel drives and off-road driving techniques has been my passion for over 20 years. Here we strive to provide the most accurate, up-to-date, information about the functionality, common faults and latest technology built into most 4 Wheel Drives.

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