Ok, i have a E320 with stock 225/55r16's (conti's) that are coming to their end of life. I have settled on the Eagle F1 GS-D3 as my replacements.

Is there any benefit in changing from 225/55r16's to 225/50r16's?

what will be the impact of changing the aspect profile from 55's -> 50's? Or that that a bad idea?

Or does anyone have any other recommendations?

John

VERY bad idea to change the overall diameter of the tire/wheel, which is what you would effectively be doing by going with a lower aspect ratio and same width. Throws off the speedo/odometer, could effect the stability electronics, and generally looks ridiculous.

Ok, thanks for the reply, im learning....

According to this cool tire calc site, i can go to a 245/50r16 and the speedometer would be the same..but i would get a wider higher performance tire

http://www.miata.net/garage/tirecalcold.html


John

Stick with the OEM size on the OEM wheels. No real point to go with a really wide high-performance tire with the 16" stock wheels and suspension set-up. They'll fit, but you run the risk of introducing some funky handling dynamics, and the tire may look too large for the relatively small wheel. You're better off going with some 17" wheels if you really want wider rubber, but the F1 GS-D3s will improve handling even in the 225/55-16 size.

With all due respect, I have never spent time around a forum that had as much misinformation spewed forth. Changing from a 55 ratio to a 50 certainly will cause you no problems. As for looks, it will barely be noticable and the same is true for performance. Yes your car will handle better, all else being equal, but probably not enough that you will feel a difference.
My comments are not aimed at this forum in general because I believe this is a great forum. Its just that too often people chime in when the don't know what they're talking about. Sorry!

Hoop, are you kidding me? Are you implying that changing the aspect ratio will not affect the overall diameter, or that changing the overall diameter won't affect the speedo/odometer?

And why, exactly, do you think handling will improve with a lower aspect ratio (width, tire brand, and pressures being equal)?

Yes Alan, your speedo will be effected marginally but not enough to worry about. As for why I "think" handling would improve with a lower aspect ratio I know that it would give you a larger contact patch= better traction and your sidewall would be stiffer= quicker steering response. Why do you think we have lower side ratios?

Putting a 225/50-16 tire on a car designed for 225/55-16 will, according to the calculator the original poster linked, throw the speedo and odometer off by 3.4%. So the car would show 51,700 miles instead of 50,000. And the diameter will be shorter by almost an inch, which means an additonal .5 inch of wheelwell gap between the tire and body of the car. And you'd be taking the risk that the car's electronics...stability control, ABS, etc...will adapt to higher RPMs than the car was designed for at a given speed.

Why on Earth would you want to do any of that.

All else (width, pressure, brand) being equal, there will be no increase in contact patch. The car will not handle better. The reason we have lower aspect ratio tires is to increase wheel width simultaneously so that the overall diameter doesn't change. Increasing wheel width is done for two reasons: (1) To increase clearance for larger brakes, and (2) "The Look". Lower profile tires do not improve handling; note that there is not one automobile or truck racing series that runs tires as low in profile as what we see on the street.

Again with all due respect, your just proving my point. Making the statement that "Lower profile tires do not improve handling" is just foolish. In the future when someone calls a tire expert as this thread did, you might want to take a pass. I'm certainly no tire expert but I know that low profile tires were not designed so we could have bigger brake or for "The Look".

You might want to do a little research, I know tirerack.com has some good basic information about street tires.
We do agree on one thing and that is that if he's already running 16" wheels, he probably does not need to see any more wheelwell. Hows that, I'll end on a positive note!

All other things being equal, lower profile tires DO NOT "improve handling". Prove me wrong.

By the way, you're the one with the wrong wheel offsets on your car, right?

Wrong! I started the thread you're referring to because I was unhappy about the off set and I've since removed them. Not only are you a know it all, I see now that your a little, little man.
Ok Alan, I'm getting very bored with this. I'm wrong and your right! Low profile tires do not improve handling and they were actually designed just so we can have "The Look" meaning big wheels and also big brakes.

GSD3's are GREAT tires! I love them. I had them on my old 550hp cobra.

But are they worth the cost if i keep my 16" rims?

they are excellent tires. but if you drive like a grandma, then they will be a waste. If you are a aggressive driver that takes corners hard and liks good wet weather traction, then yes they are worth it.

or should i start looking for some 17" or 18" rims, and go that route? Since the price of the tire is almost the same. I would like to get better cornering, performance.

Can I just bolt on 17's? Will any MB 17" fit?

depending on the offset and bolt pattern, 17's or 18 will fit fine. Not all MB rims will fit, but any CLS or E-class rims will fir ur car with no modifications.

Eighteen months ago, I purchased a set of BBS 18" wheels and mounted 245/45x18" GS-D3s on them. When new, they were exemplary tires - quiet, grippy, very responsive and excellent in the rain. Alas, at less than 10,000 miles they have become so terribly noisy that I will probably remove and discard them for something quieter.

I realize that alignment issues on the car could have produced the uneven wear that creates the noise. However, my other set of tires, Michelin Arctic Alpin snows, have worn evenly and remained quiet over roughly the same number of miles. At this point, the snows are markedly more silent than the GS-D3s, not the usual state of things!

I would not buy another set of GS-D3s