Pros and cons of low profile tire

[felix]

Found this picture in another thread and I'm really digging the low profile tire on the ltz wheels.
I dipped my wheels gold

and I'd like to keep them but I feel the tire has too much meat. Was planning on getting a lower profile tire, say 40 series but keep the stock width. I know that will expose the wheel well gap even more but are there any other down sides to a smaller tire i.e. mileage, speed?
Thanks in advance for the help

I will race any mini van on the streets....

 

[Black Turbo LTZ]

Found this picture in another thread and I'm really digging the low profile tire on the ltz wheels.
I dipped my wheels gold

and I'd like to keep them but I feel the tire has too much meat. Was planning on getting a lower profile tire, say 40 series but keep the stock width. I know that will expose the wheel well gap even more but are there any other down sides to a smaller tire i.e. mileage, speed?
Thanks in advance for the help

I will race any mini van on the streets....

I know you said you want to keep the stock width..but you could safely go 215/45/17 or push it to 225/45/17 ..40 profile at 205,215,225 will throw off your speedo and not to mention that pic is photoshopped to make the LTZ wheels look like 18,19's

 

[Anthony]

Yup. Shopped.

 

[felix]

Yup. Shopped.

Son of a b!tch. Didn't notice it was shopped

I will race any mini van on the streets....

 

[sx sonic]

As mentioned the smaller profile/diameter wheel will throw off the Speedo, which can be corrected thru a tune.

Your RPMs per a given speed will go up aswell, not the best at math so I'm not sure how big the change would be. MPG will also take a slight hit.

 

[ahtoxa]

If you're talking about keeping the same overall diamater of the tire but going to a lower profile (via larger wheel), then the benefit of low profile tire is faster responce during turn-in and better stability mid-turn as there's less sidewall roll.

There's a limit to it, though, and you get to the point of rapidly diminishing return.

But the lower the profile, the harsher the ride. Since this necessitates larger wheels if you want to keep overall diameter the same, you risk increasing unsprung mass, which is detrimental.

 

[laborsmith]

Would there not be a balance by going to a larger wheel and a lower profile tire: more weight for the wheel offset by less weight for the tire?


Laborsmith

 

[ahtoxa]

Would there not be a balance by going to a larger wheel and a lower profile tire: more weight for the wheel offset by less weight for the tire?


Laborsmith

There are some variables here. Not all tires are made the same and there are tires that are light and tires there are heavier. You can also spend a good coin and get larger wheels that are actually lighter.

So I'm gearing this statement towards most cases, most applications and most budgets. Generally speaking metal/allow is heavier than rubber by density and mass, so increasing wheel size while decreasing tire profile will still net you a heavier wheel/tire combo, increasing unsprung weight. Again, there are certainly exceptions, especially when spending good money on quality wheels.

 

[JohnT]

I've run 215/40/17...not a really significant difference, like 1mph at 60...the stock tire is 25.1" tall and most of the options you list are very close. Tire weights vary wildly by type and construction. Pick a tire because its a good tire and fits well on the wheel. If you go down to a 40 series you may need to stay narrow to get it on a stock 6.5" wide LTZ wheel.

Mileage would potentially take a hit, but it would be lost in the noise unless you drive a crapload on the highway.

Now I may try to run a 23" tire on a 15" in the future for my LTZ, not something I would try on the RS with the short gearing, but it will bring the LTZ a little shorter gearing.


As an aside, no one seems to ever think about moment of inertia for rotating wheels/tires...I've always wanted to measure the moments for a bunch of different wheels and see how well they correlated...Often there is just a bunch more meat on the hub and the moment is similar or the same despite the wheel being heavier.