55 series tires versus 60 series

[122838B]

The tire store is trying to talk me into buying 235-60 series tires for my new 16 X 7-inch rims for my 90 coup. I had wanted to use 235-55 series tires. But he said they would ride too rough and I would feel every bump in the road without that much improvement in contact with the road. Is this guy overloaded with 60 series tires or does he have a point? I am no boy racer and value the great cruising ability of the Reatta.

[Guest F14CRAZY]

To me, thinner is better. Less "mash/mush" when cornering hard.

I checked again, and our Select 60 has 225x55x16s, and they do look a lot better than something thicker. I think it rides pretty well, and corners much better than my car when I still had the stock size on the stock 15''s.

[Barney Eaton]

Here are the numbers

Your factory 215/60r16 have a sidewall height of 5.1 in and 771 revs/mile

The 235/55r16 that you want to use is also 5.1 and 770 revs/mile

The 235/60r16 they want you to use is 5.6 and 773 revs/mile

The only reason the 235/55 might ride harder is if it has a stiffer side wall, as you can see it is not any shorter. I vote for the 235/55

[Reatta45]

Barney you are right but I think you made a calculation error? the 235/60r16 are a taller tire and so would have LESS revs per mile than the smaller tires. The actual revs for the 235/60r16 figures out to 744.

If the 235/60r16 would fit I think they would LOOK better as they will fill the wheel well? As far as the ride or side wall flex or scrub lean, if you have a performance rated tire that can run higher pressure like 51 psi you will find that is not an issue on todays tires.

This question dose bring up something I have wondered about? Is anyone actually running 235/55r16s on their Reatta? Are you having any clearance issues? KennyV.

<img src="http://forums.aaca.org/images/graemlins/confused.gif" alt="" />Sorry ... I wanted to ask about anyone running 235/60r16...

[Barney Eaton]

I did make an error....not in calculating, but looked at the wrong tire...the number I used was for a 15 inch.

Clearance is not a problem using a stock Reatta wheel. I am running 245/50r16 without any problems. PS...I happened to have the 245/50 and that is the only reason they are on the Reatta, I am not recommending that size.

[Guest F14CRAZY]

i used pimp 18''s and had no rubbing. sorry i can't remember the tire size. speedometer was one mph off.

[Guest EDBS0]

tire size calculator

[olbuickman]

I am considering replacing my stock,aluminum 15" wheels and tires with a set of 17" chrome wheels and tires off of a 2007 Buick Lucerne. My question , do you think the 17" by 7.5" chrome wheel with continental touring 235-55-17-98s touring tires will clear the wheel wells and will they ride ok. I have a Black Ranier in the garage which is my main driver, it has the chrome wheels,they really set off a black car. Next to the Ranier is the black Reatta with the "ugly Betty" aluminum wheels and anemic looking 15" blackwalls. Your thoughts. Thanks Frank <img src="http://forums.aaca.org/images/graemlins/smirk.gif" alt="" />

[Barney Eaton]

The 235/55r17 may be a problem. The diameter of your factory tire was 26 inches. If you look in the front wheelwell and measure the gap between the top of the tire and the bottom of the spring mount, you will see that there is not much more than 1/2 inch. The 235/55/r17 is 27.2 in diameter and you will quickly loose the space. You would need a 235/45r17 at 25.4 to maintain the clearance. There are some other 17" sizes that might work but the 235/55 is too close to chance.

Also you need to get the dimensions for the lucerne wheel...the distance from the mounting surface to the back of the rim.

[Guest Ranger]

I'm running Eagle LS 225-55-17's on Konig Monsoon wheels, it looks a little tight on

the forward upper quadrant when the wheel is turned inward, but no problems. It doesn't ride like the luxury cruiser, but I don't want that ride from the Reatta.

[padgett]

My experience is that the offset is just as important as the diameter. A factory 7" wide wheel in 5x115 will usually have a 46 mm offset. A lower offset (say 38 mm which is common in afternarket wheels) will stick out further and increase the radius of the turning arc of the wheel. This is partcularly important when the wheel is turned to full lock.

What I have seen is that a 26.5" diameter 225x60x16 on a 16x7 wheel with 38 mm offset is about as large as you can go.

[Richard S]

Ranger, do you know the offset of the 17" monsoons?

[Guest Ranger]

I don't. If it's something I can measure, let me know how and I'll do it in

the morning.

[Guest F14CRAZY]

I googled for the Koni specs. Looks like it's 40 mm