Is 245/50/16 tire OK on a rear 7 inch rim on an 84 Carrera?

[jporsche2]

Hi Guys,
My 84 Carrera has 6 x 7 wheels.
I need to replace the tires. They got old.
I'm going to buy 4 BF Goodrich g-force Sport Comp-2.
The price is right and good enough for my occasional use 84 Carrera.

I'm thinking of using 245/50/16 tires in the rear (because 245/45/16 in unavailable).
The rear rims are 7 inch wide.
Is that OK?

I'm thinking of upgrading the wheels some day in the future to 7 x 8s.
So it would be good to start with larger tires.

I'm thinking of staying with 205/55/16 in the 6 inch fronts
although I'm tempted to go to 225/50/16 in the 6 inch fronts.

Thanks in advance.
Jay

[DanielDudley]

8'' is the generally accepted minimum width for a 245 tire. You can mount them on a 7 inch rim, but tire shops don't like to do it. And you might think you need to run more tire pressure, but the reality is that you will wind up running lower pressures for correct contact.

Running a set of correctly sized tires to your 6&7s would yield better handling and responsiveness.

[gliding_serpent]

Some racers run thinner wheels to reduce unsprung weight. I know folks who run 225's on 6's and 245's on 7's.

[Bill Verburg]

Originally Posted by jporsche2

Hi Guys,
My 84 Carrera has 6 x 7 wheels.
I need to replace the tires. They got old.
I'm going to buy 4 BF Goodrich g-force Sport Comp-2.
The price is right and good enough for my occasional use 84 Carrera.

I'm thinking of using 245/50/16 tires in the rear (because 245/45/16 in unavailable).
The rear rims are 7 inch wide.
Is that OK?

I'm thinking of upgrading the wheels some day in the future to 7 x 8s.
So it would be good to start with larger tires.

I'm thinking of staying with 205/55/16 in the 6 inch fronts
although I'm tempted to go to 225/50/16 in the 6 inch fronts.

Thanks in advance.
Jay

The tire engineers say
yes, a 245/50 x16 can be used on a 7
no, a 245/45 x16 cannot be used on a 7

The 255/50 has a taller more flexible sidewall that generally wants a narrower wheel.

The question that should be on your mins is do I really want to use 245/50 vs 225/50, the answer depends on how much you value responsiveness to the application of the go peddle.

245/50 is ~25.7" tall oe 225/50 is ~24.9" tall, that extra .4" of radius kills acceleration. For multiple reasons, one being the mechanical advantage of the tires radius another being the increased weight further from the axis of rotation this tire is a performance killer.

One of the multiple good points of a 245/45 on 8-9 is that it's ~24.7" tall which is a nice little boost to acceleration curves.

besides the effect of tire height on acceleration the effect of the more flexible sidewalls on handling should also be considered.

using a narrow wheel to save weight is a false economy on a performance car. Now if you are in a fuel economy or plush ride contest narrow is certainly better.

[Shaun @ Tru6]

I have these.

FS: BFG G-Force Sport Comp 2 tires

[stephen1070]

Why not the standard fitment of 225/50-16 on 7" wheels this size seems just right on 8" wheels in the rear.

[Bleedsblue]

If "feel" is a concern at all, I wouldn't. I didn't even like 205/225 on 6/7 (unless we're talking much stiffer sidewalls than Comp 2s). I could feel all four tires' sidewalls flex coming out of corners, and the front pair took away quite a bit of steering precision IMHO.

[rattlsnak]

245/50s are WAY too tall..

[3rd_gear_Ted]

The Hankook C51 & Nitto NT-01 for track use are 50 series tires. Not sure why, once heard they are for heavier race cars that need sidewall flex. ????
Sure wish they would design them specifically for 911 Porsches

[Racerbvd]

NO, if running street tires, you need a minimum of a 9" rim, otherwise you are losing any benefit because the sidewall is bowed so much, plus you will look like an idiot with those ballooned tires. Stick with 225/50s on the 7s, they work much better.

[jporsche2]

Thank you for all your views.
Will the 245/50/16 on the rear 7 inch rims rub anywhere?
Will the 225/50/16 on the front 6 inch rims rub anywhere?
Thanks in advance

[Bill Verburg]

Originally Posted by jporsche2

Thank you for all your views.
Will the 245/50/16 on the rear 7 inch rims rub anywhere?
Will the 225/50/16 on the front 6 inch rims rub anywhere?
Thanks in advance

Nobody is suggesting that 225/50 x16 be used on front 6, they fit the wheel but they will probably fit the wheel wheel.

one of the issues is that 6 is the narrowest wheel that the tire engineers are ok w/ for a 225/50 x16. It fits but is less than optimal for performance.

One assumes that the purpose of fitting larger tires is to optimize performance. But apparently not.

[Racerbvd]

Originally Posted by jporsche2

Thank you for all your views.
Will the 245/50/16 on the rear 7 inch rims rub anywhere?
Will the 225/50/16 on the front 6 inch rims rub anywhere?
Thanks in advance

The 245s could roll off the rim under hard cornering, then tire rub will be the least of your problems, also, bubbled over "could", depending on the tire, rub an oil line & that could be a real issue, but generally only if the alignment is jack up or the car had been damaged. 225s on Sixes in the front, NO.

Why not just run the correct size tires? Many of us have been playing with these cars for decades (and have tried the odd, incorrect combos in our misguided youth) and are going by experience, trial & ERROR (I did say misspent youth . What may work with track cars with track tires does not work with street tires.

[DanielDudley]

Bill and Byron are very knowledgeable. They are trying to help you. Really.

You won't be happy. I have seen a lot of guys come to different forums over the years complaining about ill handling 911s, and swearing up and down that it wasn't the tires. It often turns out to be the tires. Can you mount stubborn and cheap on your rims ? Yep, you sure can.

Good 205/225 combos on 7&8s are a nice set up, and can easily be transferred from 6&7s. They fill out the wheel arches nicely. Nobody wants to tell you what to do, but you did ask.

Running 50 series 245 tires on the back will really point out to you just how tall second gear is on a slow corner. But don't take my word for it, feel free to find out for yourself, every time you drop below the power band.

Why is it that there is never enough time or money to do things right the first time, but always enough time and money to do it over again when it doesn't work out ? GLWT.

[Bleedsblue]

Awesome picture!

[Shaun @ Tru6]

here's what 205/55/16 front and 245/50/16 rear looks like.

[jporsche2]

Hi Guys,
OK. I got it.
I just wanted fatter tires but those 245's don't seem to work.
Thanks for saving me from my own stupidity! :-)
It's 205/225 for my new tires.

Did you mean 205/55/16
or 205/50/16 for the 6 inch fronts(perhaps 7s in the future)?
Does it matter?
I plan to upgrade from 6/7 to 7/8 sometime in the future.
Thank you very much for all of your help.
Jay.

[jporsche2]

Hi Guys,
Clarification on the 225.
For my 7 inch rear I'll get 225/50/16 right?
Thanks.
Jay.

[Bill Verburg]

Originally Posted by jporsche2

Hi Guys,
Clarification on the 225.
For my 7 inch rear I'll get 225/50/16 right?
Thanks.
Jay.

On 6 & 7, 205/55x16 & 225/50x16, You could also use 205/50 x16 and 225/45 x16 If the car is very low.

[jporsche2]

So I can use a 205/50x16 front with a 225/50x16 ?
(since the BF Goodrich g-force Sport Comp-2 doesn't have a 225/45x16)

Does the 205/50x16 have a smaller diameter than 205/55x16?