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 3^rd and 4^th 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.

INTERESTING READ: 33″ vs 35″ Tires (Size/Weight/Height)

Silverado 33-inch tires and no lift – Options

The internet is rife with queries about people wanting to know if it’s actually possible to run a bigger than 33” tire on a stock suspension without issues. How many actually end up running bigger than 33s on stock suspension is another story altogether. Most will at a minimum opt for a leveling kit or some wheel spacers to allow better clearance inside the wheel arches and increased clearance from the UCA.

Once you go bigger like a 2” or 3” lift with a combination of aftermarket rims with a more negative offset things become a lot easier, but also a lot more expensive.  

So the absolute biggest tire you can squeeze in a stock Silverado, without a leveling kit, and no suspension kit would be a big 33”, but it might require a bit of wheel well modifications, especially at full lock in reverse.

A 33” tire can be in the form of any of the following sizes depending on if you intend to go off-road or you just want a more aesthetically pleasing look.

However, if you decide to fit aftermarket wheels with a more negative offset you will be able to run a 33” much easier without any other modifications.

So as mentioned from the outset, if you really want to fit a 33” tire on a stock suspension on a 3^rd and 4^th Gen Silverado, you’ll need to do some wheel well modifications first.

Let’s find out exactly what is required.

Cutting and trimming your beloved truck

The problem with most trucks running IFS (Independent Front Suspension) setups is the clearance of the UCA (Upper Control Arm) as well as wheel backspacing. The Silverado 1500 might be a large truck, however, most manufacturers limit you with the wheel arch clearance. This is what severely restricts you from fitting wider tires like a fat 33” or bigger 35”. Running anything bigger than a 33-inch tire on a stock suspension and stock rims definitely WILL rub. 

What needs to be trimmed to run 33s? The mud flaps will touch and the plastic fender insert will need some massaging or pulling back to allow the wheel to clear when at full lock. You’ll need a heat gun to mold and massage the plastic fenders out of the way. You’ll have to take it on a case-by-case basis and modify it as it touches. This is especially necessary when reversing.  Unlike the 3rd Gen Tacoma, you don’t have to worry about cab mount chops or crash bars as is the case with the new Ford Rangers.

What about skinny “Pizza Cutters”?

If you want the height for improved ground clearance when going off-road but don’t want the hassle of modifying your wheel wells by trimming and massaging the plastic liners then there’s always the option of a skinny tire upgrade. This option will offer improved ground clearance since it’s a taller tire than stock, but narrower, hence the nickname, “pizza cutter”.

These tire sizes are roughly 32.7” and come in the form of a 255/85 r16 or 255/80 r17 which is 33×10 (roughly) and will fit on a stock suspension with no lift and little to no rubbing. The width of a 255 works well, as long as you don’t fit negative offset rims or thick wheel spacers. If you don’t mind the look of the skinny width, then this is a feasible option since “skinny” 33s on stock wheels are well within the wheel well. It might just look a bit weird on such a big butch truck like a Silverado.

But, what if you really want to fit 33” tires like a 285 width on stock suspension, will adding spacers work?

Let’s find out.

Will a small leveling kit or wheel spacer help with 33” tires?

Usually when wheel spacers are mentioned, many will quickly give you their opinion and fob it off as a bad idea. The truth is they aren’t nearly as bad as people make them out to be. They definitely aren’t the fix-all of suspension woes either, however, they will offer improved backspacing, which allows for a slightly wider tire. It’s a very affordable way to improve the aesthetics and ride height of your Silverado.

Wheel spacers have a similar effect to fitting wider tires or more negative offset wheels. Yes, it might improve your backspacing somewhat, and even clear your UCA better, however you still need to take into consideration the clearance of the upper inside of the wheel arch at full articulation. You don’t want to go too wild with the spacers. Remember, very aggressive wheel spacers place more strain on those wheel bearings, so be cautious!

Installing a spacer kit above the front coil struts and springs is another affordable way to get extra wheel clearance. This does not improve off-road performance or load-carrying ability, although it will increase your approach angle slightly since the body sits slighter higher. Fitting a leveling kit means you’re still bound to a 33” tire but there won’t be much need for wheel well modifications. If you really want to fit a bigger 33″ (33.9″) tire, and you have a 2″ leveling kit, you might need to do some minor trimming of the fender liner.

Big tires on a Silverado and fuel economy

With any upgrade, comes a small tradeoff and a big tire upgrade is no exception. Fitting wider, heavier tires definitely comes at a price and since the tires are positioned below the suspension, they fall part of the unsprung weight of the truck. The quickest way to increase fuel consumption is by increasing unsprung weight. The heavier rolling mass of the tires has a direct impact on your fuel consumption, especially when pulling off.

Also, depending on how big you go, you’ll feel a drop in pull-off performance as well due to the heavier tires needing to be pulled along. It might not even be more than 4kg heavier per tire, however, this makes is a big difference in torque transfer on the wheels and if you decide to go bigger than 33” then re-gearing of diffs should be a consideration since there will be more strain on diffs and other drivetrain components.

33” with Suspension Kits

So depending on how high you go with the suspension kits will determine how wide and tall you can go. So for example, a 2″ suspension upgrade will clear 33” with no major issues or modifications like cutting and trimming. If you opt for a 3″ suspension package it will allow you to safely run even bigger than 33-inches without any issues.

Conclusion

So the takeaway here is, without a 2” or 3” suspension upgrade or leveling kit and want to fit 33” tires, you’ll need to do extensive cutting and trimming of wheel wells. You’ll be limited to a smaller 32-inch, “pizza cutter” tire. A leveling kit will help with wheel clearance, however, the best option for your Gen 3 or 4 Silverado is to opt for a 3” suspension kit if you want to run wide 33” comfortably. If you can include more negative offset aftermarket wheels, it would improve UCA clearance and backspace with no need to do any additional modifications.