As far as rubber on the ground goes i'm a believer that more is more. I know the sizes are a bit different, wondering if anyone has tried it, if there is clearance to turn full lock left/right?

 

 

I'm interested in the science of this. It has been proven time and time that more contact area = more grip, which both improves braking & high-G turning relative to the weight of the car.

 

I don't have an opinion on the subject, but I think what he's saying is that wider might not necessarily always equal more contact area. I would guess there's something about pounds per square inch of contact area and how much the tire flexes. I too am interested but not enough to give myself a headache thinking about it.

 

Right. Theoretically, the contact path should have the same area. So, if it gets wider laterally (side to side), then it also gets narrower longitudinallly (front to back). Not including tire stiffness effects.

 

Exactly correct. The weight of the car isn't changing when you add a wider tire, so the force on the tire stays the same. Taking out the variables like sidewall stiffness and air pressure, the contact patch area is exactly the same size, only now in a different shape because you've changed how the load is spread.

If you look at dragsters, the more powerful they get the taller the tire gets. This is to create a contact patch that is more longitudinally shaped (front to back) rather than laterally (side to side), since they only care about preventing wheel spin rather than turning. Same thing applies to off-road vehicles who are constantly trying to fit a bigger tire under their rigs, both for increased ground clearance and reduced wheel spin when climbing obstacles.

If you want a truly larger contact patch, you air down the tires or play with sidewall stiffness and wheel dimensions; there's a fun calculator for this here:

BND TechSource - Tire Data Calculator

The supercar industry has created this misconception with large wheels and wide tires, not to improve handling so much as to look cool. The dodge viper doesn't have stupid wide rear tires to put the power to the ground so much as it does to keep the light back end from coming around on you. It gets more complex from there when it comes to tire sizing, but that's a rough idea of things.

 

Search engine (I use Duck Duck Go) is your friend:
https://www.tirerack.com/tires/tiret....jsp?techid=10
https://www.roadandtrack.com/car-cul...-tire-patches/
https://www.discounttiredirect.com/learn/contact-patch

 

Ah!

It really just clicked for me in the last 5 seconds what you mean. Yes, I guess I have been rather mislead all of these years, but the first Tirerack link really clicked it for me. So, from what I can understand, while wider tires might be better for lateral movements, they are not necessarily better for medial movements (braking, acceleration). Am I saying this correctly?

 

I come from a world (roadracing) where lateral traction is everything. Give me the fat rubber.

 

Reminds me of a top gear episode years ago where they were "track prepping" 3 cars on a $2000 budget, and Richard Hammond added wider tires and lowering springs with stiffer shocks to his car, and the result was that the car was actually a bit slower around the track.

Agree wider not always better, but I did a +1 size for the front on my F-type, as I had room and felt with the 2wd model I wanted to do everything possible to minimize understeer since my less-than-expert driving skills were already taxed dealing with power on oversteer in a track setting. At the end of the day, not much noticeable difference, but it looks better.

 

This was the initial spirit for the OP, as I am in the northeast I am almost surrounded by tracks.