I was just thinking about tire performance. The standard size for our tires is 215 50 R17 93V and is the only size recommended by Acura. There are no optional sizes. Ok, with that said, if you increased the height to 225 or 235, wouldn't that take the flatness out of the corning to the point of hurting tire perfomance? What would happen if you increased the width also? Would you increase corner performance? I suppose you could come out of the hole better on a launch. A tire dealer I went you yesterday seemed to suggest that putting a larger tire on the car would not only hurt performance, horsepower,
speedometer calibration and blow the alignment ,but could void the car's warranty. What's your opinion?

 

1. 215, 225, 235 is the width in millimeters. Divide by 25.4 to get the width in inches.

2. I wouldn't mess with changing the overall diameter of the tire. Anything between 25.1 and 26.1 inches is probably okay but it won't affect handling on it's own.

3. A wider tire in general will have a wider but shorter contact patch. This will make the steering stiffer and provide more lateral grip.

4. At the same time, going wider on stock rims will soften the sidewall somewhat. I had 245/45/17's and the grip was better under light/medium cornering but there was more bodyroll under hard cornering because the sidewall flex point is no longer in the middle of the sidewall (ie. it moves towards the shoulder ie. road).

5. Wheels are stiffer than tires. Thus to really make the handling better you should go to a 18 or 19 inch tire. At the same time, you will adversely affect smoothness and ride quality by doing this because the tire is your friend over bumps.

hope this helps.

 

It will (99%) not hurt alignment, and will not void warranty, you should find another tire dealer! If the tire is bigger it will be harder to turn, so could hurt performance (launch). Wider tire gives you more rubber on the road. I went from 215/50-17 to 235/45-17 (OEM rims), and actually expect my speedo to be closer with the wider tires (as the OEMs were off about 1%). YMMV

 

In the "Car and Driver" July 2002 issue, page 76, Hobson's Choice in the article that pitts the BMW 330I against the six speed Acura CL-S, under "Lows" for the Acura, it is quoted, "Government-issue styling, A BIT SKIMPY IN THE TIRE DEPARTMENT." This suggests that they think larger tires would help make the car perform better.

 

Well . . ... that's perform "better" on a sunny track and or their test conditions. In everyday driving tires are not going to make a difference. In the rain or at .75 g you'd notice a difference.

 

regardless of this scientific data about the sidewall, etc....a wider tire (235/45/17) easily outperforms the stock tires......ive got stock tires, a freind with a CL-S has 235/45/17 toyo proxies and his cornering ability, traction off the line, etc are waaay better than mine, we can take the same turn at high speed and my rear tires will start to break loose and his will stick like glue to the road...i dont care what the physics of the matter say, the wider the tire is, the better off you are...thats how it is in real world experience

 

Granted, and true. However, if that "better performance" is costing you 3 mpg due to higher rolling resistanace is it really "performing better". You don't take corners at maximum grip every day. Nor do you use maximum out of the hole acceleration every day. So, do you buy tires bases on 90% of the normal driving you do, or do you buy based on the other 10%. You make the call!

 

So what's everyone saying, Just buy the stock Michelin tires again when you wear them out instead of going for wider tires?

 

You can get a million different opinions on tire sizes.

It is true that, everything being equal, a wider (not necessarily taller) tire will give you better cornering and to a lesser extent launch capability. There is little trade off in increased rolling resistance and don't worry about alignment - if they said it will void your warranty they are either clueless or lying.

BUT, in the real world everything is NOT equal. All tires are made differently. The basic construction (belts); tread compound; tread design; aspect ratio (just because 2 brands are listed as the same size does NOT mean they are exactly the same dimensions); sidewall stiffness; etc.

You will get a much better performance increase by changing tire brand/models than by messing around with tire size. In other words, get rid of those garbage Michellins.

Once you've selected the tire best for your use, considering wet & dry handling, braking, ride, noise, mileage and $$$s (remember everything is a compromise, get something here - give up something there) THEN size can get you something.

 

No, not necasarily buy the Michelins again, but that tire size doesn't get you an more "performance" in normal everyday driving. If you're auto crossing or racing you'd be wize to take size and brand into consideration.

Starter: it's true the Michelin's aren't the best for maximum lateral grip. However, the OEM tires do have one of the best rolling resistance numbers in the entire industry. I for one lost 2.7 mpg when I switched to Falken.

 

I would shoot for wider tires...better grip and definitely better tires than the michelcraps that come with our cars.

 

personal preference...if u don't want the performance tire and like the ride quality of the stocks, keep the stocks...if u want performance, and u live up north where there's snow, consider the all-season performance tires...if u want performance and live where no snow's around, u have many more choices...there is no 1 single 3-season high performance tire that outshines all others, but a few of the favorites here that work with our setup include Toyo Proxes, Khumo ECSTA, Pirelli P7000, and Michelin Pilot Sport

 

Guys , hemants in Toronto offered the best explanation from a technical point of view and it is very valid. A lot of other explanations are mere subjective opinions that are not valid.

 

Don't "poo poo" the standard Michelin Tires. They are performance V rated to 149 mph and will last way longer than Z rated. Acura wasn't going to sell you a performance car with a standard type passinger rating.

 

Would you all agree that keeping the 215 size, but going a litter wider to 45's would be best in up grading performance? Now remember, I'm not talking about looks here, just performance.
I think I have this right...the 215 is the diameter and the 45 is the width?

 

Pappy, read my post again - tire brand/model will buy you more performance than going up a size. You may lose some mileage & ride comfort but they will stick better. Also, do you want wet or dry performance (lets see, Florida = the occasional hurricane. I'd go for wet performance. 8-)

 

NO, not necessarily. Every Road &Track tire test I've ever read shows the switch in rubber compound from lesser speed ratings to Z or higher speed ratings gets you the most performance. Of corse the down side is the tires wear out faster!

 

215 = width in millimeters

50 = aspect ratio, height of tire wall as a per cent of width (the 215/50 would have a sidewall height of 107.5 mm, or 50% of 215).

17 = diameter of hole (where wheel goes)

93 = weight setting (higher = stiffer sidewall)

V = speed rating

A wider tire would be 225, 235, etc. The two digit number (45, that you quoted) is the aspect ratio.

 

Thanks Slimey, I stand corrected...I had it backwards. Ok, I meant to say how about 225 width and keeping the same height at 50. The sidewall remains the same size, but the tire is a little wider. Wouldn't that increase the performance without changing things too much?

 

The sidewall doesn't remain the same on a 225/50 tire when comparing it to a 215/50 tire. It's 50% of 225 versus 215. A little taller, a little wider...

 

Thanks Scrib and all my technical advisers. I guess what I'm trying to do here is figure out the best formula for performance.

 

A 225/50 or 235/45 series tire with some Comptech sways would be just fine!

 

For some more fun with tire sizes check out some of these online tire calculators and see what tweaking your 215/50-17 to something else will do.

http://gs.tolan-hoechst.com/ (click on tire & wheel calculator)

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

http://www.dakota-truck.net/TIRECALC/tirecalc.html

Put some truck tires on your CL-S and see what your speedo does. Fun Fun Fun!

(as others have said 235/45-17 will keep the speedo happy in 17 inch tires; 235/40-18 in 18 inchers, and so on)

 

I just spent countless hours researching all the pros and cons.

Everything you do ends up being a trade off. Some will be more negative than others. So what are you really trying to accomplish?

Handling, responsiveness, acceleration, etc? Please respond with those points and think about weighting them. I even created a spreadsheet with all the various specs and weighted each of them according to my requirements and impact on the manufacturer's specs. Mine are the HX MXM4 215/50/17 on the TLS. So keep that in mide when I cover my specs.

To me weight of the tire and wheel were a major factor. That immediately put me in the 17" catagory and eliminated several brands because of weight.. Then I narrowed it down to dia, tire and tread width, RPM, traction, treadwear and price.

In the end I went with Konig Appeals at 18.2lbs and 225/45/17 Toyo Proxes T1-S which were close to 20lbs. That reduced my overall weight by a tad over 8lbs.

All this while maintaining all the other specs within a fraction of the OEM tire.

Dia was off .4" which will impact the speedo no more than 1MPH at 60.

Section width was .2" wider with the Toyo, but tread width was .8" better than the OEM tire. This was a big positive as it lends to better handling without too wide of a tire. And of course, the Toyo is a AA/A rate tire as well.

Note, I had several people including the tire dealers ask me why all the extra effort. All 225/45/17 are the same when it comes to sizing.

THIS IS A BIG MISPERSEPRTION!

I went to each manaufacturer and found that no 22/45/17 was alike. So you really need to do understand what you are wanting and then weight the variables. It's worth it in the end.

RUF

 

RE: 235/45-17 or 225/45-17 (with stock rims).


1. The braking is mainly a function of the grip. A good max-performance/ultra-high performance tire can keep you from running into someone.

2. The stock tires may be good for rolling resistance and long life, but they squeal like piggies, don't like certain types of pavement and have low grip on some types of asphalt.

3. As Ruff mentioned, spend some time "digging" for what you looking for (low noise, grip, all-season, max grip, etc). You might even be able to get a ride from a buddy or member.

I gave a ride to a member with just the Toyos on the car, and he was amazed -- and NO, we weren't driving a 1.1Gs on ever turn.

Some of the 235/45-17s (which give you the closes speedo match in a 45 series) may present problems depending on brand and model (the Toyo T1S can be "difficult" to align on some machines when used with the 2001-2002, 17x7", OEM wheels (the sidewall protector is so thick, that it is hard to get some a "grip" on the wheel). The 225/45-17 will fit without a problem. And, there are some 235/45-17s that will work with no problem..

As Ruff said, the 225 (OR 235)s ARE NOT ALL THE SAME -- the actual section width and tread width varies.

Sometimes people make an assumption that a 225 is a 225 is a 225 and this is not the case (a trip to Tire Rack's website will take care of this assumption).

The tires, depending on make, brand and size can make a huge difference in safety and handling.

 

Well I need new tires soon so I guess I will just go with another set of the stock tires.

 

You'll regret it. Those tires SUCK.


Get the toyos...you'll love'em.


My buddy has the S03's on his car and they are awesome too.

 

A couple more things to keep in mind:

1. The original TL/CL were calibrated to 25.7 inch diameter tires (205/60/16). No one has confirmed that the Type S were recalibrated for 25.5 inches. I HIGHLY DOUBT IT. Thus the spec on these cars should be considered 25.7 inches, not 25.5. Thus, 225/50/17 would be as good if not a better choice than 225/45/17.

2. The most drastic improvement is to be had by changing the rubber as EricL says. I have had both 245/45/17 Firehawks and 215/50/17 Dunlop 9000's and the grip and handling of both these configurations is head and shoulder above the MXM4 which are pieces of crap. My Nokian NRW handle better than the MXM4's. The Michelins are just too hard. This may be done to improve the life of the tire and get fuel economy ratings up for Acura's fleet which is a big deal.

Thus, choose the right rubber first and then consider size because unless you widen the rim, widening just the tire is a tradeoff, especially if you go outside of spec like I did.

 

That's an interesting point that I have not though of. It would explain why some are getting speedometer and odometer readings that are 1 - 4% off.

Someone needs to do speedo/odo tests on their Type S with some different tires (215/50, 225/50, 225/45, 235/45) and figure out which one really keeps the speedo/odo accurate.

 

I was just looking at the Yokohama AVS ES100 in a magazine. What a great looking tire. Does anyone know anything about them?

 

DON'T DO IT!

Assuming the CLS has the same Michelin MXM4s tires, and you want to stay stock, look at the following tires.

Falken Zeix 512 215/50/17
Yokohamma AVS ES100 215/50/17

Both tires have nearly identical dia, tread and section widths so they will not impact fit or the speedo.

The Falkens are about 2lbs lighter than the MXM4s and have a higher tread wear.

The Yokohamas weight about the same, slightly lighter, but have an AA traction rating, but a slightly lower tread wear.

Otherwise I still recommend doing some online research of the various brands.

Also, I believe the CLS wheels are 7" verses the TLS's 6.5". That extra .5" allows you to look at 225/45/17 without any impact on fit or function. In that case I would look at the:

Toyo Proxes T1-S 225/45/17s or the
Yokohama AVS ES100 225/45/17s.

Both are lighter, provide better traction and have minimal impact on your speedo. The impact on the speedo is about 1.1% or at 60MPH you will be off .66MPH. Not even worth worrying about.

There are other brands such as Kumho, Sumitomo, Pirreli and others that will fit, but they are heavy. So unless you really don't care about weght, then look at those.

However, let me tell you, weight is a factor in overall performance. One pound is not a big difference, 2lbs minimal, but 3+ is more of a factor. It effects rotational mass, braking, steering response, etc. I've even heard that there's a muliplier for front wheel-drive cars of 3x. So that 3lbs would now be 9lbs.

In my opinion, the Toyos are a bit more expensive, but offer the best overall benefit. The Yoko's would be next.

Good luck.

RUF

RUF

 

Yeah Toyos are too much man.

 

Kind of right. A 215 50 R 17 tire has a 17" diameter rim, and the 50 is 50% aspect ratio. The OEM tire is 215mmx50% high, and 215mmx50% wide.

If you want a 45, then you need to widen the tire. In our case, it does change the overall height. Common oversize is a 225 45 R17 (so 225mmx45% high by 225mmx55% wide.)


I swapped out my MXM4 Michelins for the Dunlop SP Sport 5000's. They're all season, with amazing wet/dry traction. The ratings have them pegged way better than the Michelins in snow too (don't know yet since she's still sunny up here).

With the 6 speed I found I got a lot of rubber between 1st and 2nd and some between 2nd and 3rd. With the Dunlops, the little rubber between 2nd and 3rd is all I get between 1st and 2nd. Way nicer, and almost no torque steer. Handling is top notch as well.

Not sure about mileage changes though. I've only went through a 1/2 tank around town with them on. I dropped less than 1 MPG for the 1/2 tank, so not that much.

 

My last tires were Goodyear Eagle RSA's. I like the Yokohamas better. Both were/are 215/50/17's.

 

I think I'll switch to Yokohama's 225/45/17 AVS ES100.

 

That will leave you about 1/2" shorter than stock. You could go 235/45/17 and be only 1/8" short than stock and pick up the exta width. Unless you like having shorter tires. (your speedo will read fast and accumulate more miles than actual)

 

If I was going to get those Yokohama's, what size would you recommend to keep the speedo the same as it is now, the stock size?

 

There are two sizes, other than the stock (obviously) 215/50/17 that will be the closest ---

1) 235/45/17
2) 225/50/17

 

So the 235/45/17 Yokohamas would be closest to the standard Michelin's 215/50/17's that are on there now?

 

The 235/45/17 will be about 1/8" shorter that the tires you have now. The 225/50/17 will be about 3/8" taller than what you have now. That is assuming that all tire manufactures built their tires to the standards. You will find that if you place 2 tire of the same size from different manufactures beside each other they with differ in height and width. So go to the tire store and compare the sizes you are interested in and you present model and make your choice from there.