[IridiumRS400]

A good discussion on stagger in a Bimmer forum:

Do staggered tires change handling characteristics

While I'm not the most knowlegable person in the world when it comes to handling, I did work with and manage some of the most knowlegable people in the world when it comes to handling so hopefully I can clear a few things up.

Ideally all 4 tires should be the same size and a car should have 50/50 weight distribution.

There are basically only three reasons for fitting staggered tires to a car #1 for weight distribution, #2 for all weather performance #3 due to size contraints.

#1. Generally if you have 60% of your weight on the rear and 40% on the front you want 60% of your tire width on the rear and 40% on the front.

#2. Wider tires are more likely to hydroplane and have other issues with rain and this gets to be really severe really fast, to the point where going up 25% in tire width can reduce your rain performance by 50%. The front tire width has the vast majority of the responsibility for rain performance.

#3. The front of cars has steering systems which makes it hard to fit super wide tires.

Anyways you do have it completely backwards, wider tires on the rear make the car understeer more and that will happen to any car. What manufacturers often do is put slightly staggered cars (up to 12% wider in the rear in 50/50 distribution) on performance cars, the reason for this is that the car needs a certain amount of traction to put a certain amount of power down but with today's power levels the tires the car needs will have horrible rain performance so they put slightly thinner tires up front and then calibrate the suspension to compensate for it.

The problem that people run into is when they put really wide aftermarket tires on the back, which can completely change the handling by being just 30mm bigger than stock staggering, because having significantly staggered tires changes the handling of the car in a non-linear and very dangerous way. In fact it's not even possible to fully compensate for extremely staggered tires with any handling tricks, which is why it's not a good idea to overdo it in any car, and having extreme staggering will lead to snap oversteer which is one of the most dangerous things you can have in a car, the Ferrari 599 is a perfect example of staggering gone too far and it's probably the most crashed car by journalists and even Top Gear commented on the problem where if you turn the traction control off the car will randomly spin. So you have people who put extremely staggeed tires on with no suspension adjustment which induces very severe snap oversteer and makes the car let go unevenly and negativly impacts the handling, and significantly reduces rain performance, and that's a recipe for crashing.

So the number one thing you want to avoid is staggering your tires much more than the ratio the manufacturer uses, generally increse the front and rear width at the same time.

The Hyundai Equus has about 450 hp which is about the range where you'd need to stagger tires to maintain traction without sacrificing rain performance.

Michellin's tire warranty is pretty reasonable, rear tires on cars like ours go fast because of wheel spin, and cars like ours have staggered tires because they want to minimize wheel spin.

As for manufacturers trying to induce understeer with staggered setups for safety, that's ridiculous. You can easily do that with suspension, doing that with tires is a really dangerous way to induce understeer which defeats the purpose of it being for safety.

Hope this helps in your decision-making.