2fcknfst

I got thisiameter inches (mm)26.72 (678.6)26.2 (665.6)-0.51 (-13) -1.9%Width inches (mm)9.65 (245)12.01 (305)2.36 (60) 24.5%Circum. inches (mm)83.93 (2131.88)82.32 (2091.04)-1.61 (-40.84) -1.9%Sidewall Height inches (mm)3.86 (98)3.6 (91.5)-0.26 (-6.5) -6.6%Revolutions per mile (km)754.89 (469.07)769.64 (478.23)14.74 (9.16) 2%
...

emptypockets

Wow that is just 2fcknmuch and overwhelms my pea sized brain. I get lost on how width can have anything to do with circumference they are two different planes. Until I hear a valid relationship of the two I call an astounding BS! Coming from one who believes he has and idea that performs outside of the laws of physics.

michalik.piotr

@ghostofpain, not true. had 305's on 19" HRE 540s with nothing more then H&R springs.

ScottKelly911

What size wheels do you have and what sized tires are on it currently? This would be helpful in having us determine what may be a good setup for you as well as helping you decide what tires may be good choices, as not all tires are available in all sizes. Like the PS4S's that many of us wish came in either 295/30/18 or 315/30/18 sizes so we could use them on our cars with stock sized wheels. Also, give us intended use of the car to also help us figure out what tires may be best suited to your driving, ie, canyons, track or autocross etc. Being in Seattle, I imagine wet traction is a consideration.

2fcknfst

Buddy, slow your roll - I only copied and pasted the info from a tire chart online, here:

https://www.tacomaworld.com/tirecalc...5r19-295-30r19

That's it, it didn't copy over well and makes for easier math. And if you cannot appreciate help, in any form, don't ask.

emptypockets

Sorry the way my post came off it was mostly in jest. I need to use LOL or jk where neeeded.

I will research how width can have an affect on RPM as my pea size brain believes it can't.

emptypockets

2fknfst...I posted the incorrect front tire size should be 225/40/19, using the chart the difference is .5% which is well withing Porsche's specs.

Next is to get the car raised to appropriate height and aligned to see if there will be any rubbing. Not replacing the tires/rims would be a big plus!

NoEardGoat

emptypockets

Thanks for that chart. I have misstated the front tire size in a couple of posts. Numbers don't lie but if the wrong numbers are used then numbers can't tell the truth. The tires are Michelin pilot sport 225/40/19 F & 305/30/19 rear.

Using this chart https://www.tacomaworld.com/tirecalc I found the ratio between the R&R to be within Porsche's specs.

NoEardGoat

The problem with your calculator is that it is assuming that all tires of a certain size are the same diameter which they aren't. My #'s in the chart are from the manufacture and are specific for each model. I try to use revolutions per mile because this is the most accurate measurement of a tires diameter. Not all manufactures list the revs per mile so that is when the model specific Tire diameter is used.

Nzo

Made this for myself a while back, may be helpful to quickly see what sizes will work with others

emptypockets

I looked up the dimensions for the tires on the car and they were what was used in the chart.