If this has been discussed, pls delete.

The overall diameter on the P255/40R19 Brembo tire is 27.0"

The overall diameter on the P245/45R19 GT and GT/CS is 27.7"

According to my calcs, that's about 2.55% bigger than the Brembos. Taller tire lowers the overall final drive ratio, blah blah....

Is it safe to say that it would be like only having a 3.63 axle ratio? (3.73 minus 2.55%)

 

Not accounting for the higher unsprung mass of the larger brakes/wheels/tires.

 

True! That's why I floated this out there...

I would think the Brembo wheels may be lighter.

 

I'm sure the straight line performance difference will be marginal.

 

As far as weight goes it will probably be close to a wash. The Brembo wheels aren't light at all they weigh in at close to 30lbs and the smaller (width) 19X8.5 wheel may come in a few lbs lighter than this. However, the tires on the Brembo car weigh in at 27lbs, while the 245's weigh in at 31lbs!! Yikes..my 305/30/19 on the back of my Carrera weigh less than that at 30lbs. As far as the diameter is concerned may make a slight difference but one that I think most people won't notice..other than the better ride over the Brembo equipped car.

Dave

 

According to my calculations, a car with NO brakes will go faster.

 

Haha wrong, the Toyota will be the fastest!

 

As far as weight is concerned it is probably a wash even if the Brembo package wheels are lighter. I would expect the larger 14" Brembo rotors to be heavier than the stock rotors. It is all rotating, unsprung weight.