245/40 18 going to 225/40/18 should I expect a quieter ride? - PeachParts Mercedes-Benz Forum

spinedoc · #1 04-05-2003, 04:22 PM

1991 500SL currently with 245/40 18 Kumho's. My ride is a bit rough and I some some vibration at high speeds. (Tires are great otherwise though). I am considering the Yamaha Parada in 225/40 18. Will the smaller size and width give me a substantial decrease in vibration, road noise and tire drifting? If not then I would stick with the bigger size.

omegabenz · #2 04-05-2003, 04:26 PM

You should try to get more sidewall on the tire without lifting your car up. For instance, a 215/40/17 tire going to a 235/45/17 tire you will notice much smoother because the 235/45/ is a little taller and has more sidewall. If you want a better ride, put more sidewall. And buy michelin pilot sport a/s, I really like mine, they are very smooth.

so for you 245/40/18, I think thats too wide for your car honestly. try 225/45/18, you might like that better.

manny · #3 04-05-2003, 08:21 PM

A narrower tire ( 225 vs. 245 ) will give you less thumping noise.
The overall noise of a tire is largely a matter of tread design.
You may want to consult with Luke on this.
He is the expert, that's why he makes the big $$$$$$$.

The Godfather · #4 04-06-2003, 06:04 AM

Tire brand will make a difference! Khumos are kinda "cheap." If you go with higher end more expensive tires like the michelins, you will (should) get less noise. I had "Capitol Negociator Tire Pro's" tires, and they were noisy as hell. I then got Bridgestone S-03 and less noise now!

suginami · #5 04-06-2003, 02:05 PM

Lower profile tires requires stiffer sidewalls to support the tire, thus providing a stiffer ride.

spinedoc · #6 04-06-2003, 08:29 PM

OK for my next question. My current 245/40 18 tires rub the fenders because the offset of the rims. I want to keep the rims but go for a smaller size tire not only for comfort, but also to reduce rubbing. I definitely have to go a bit less wide, but Im not sure if a higher sidewall will cause more rubbing even it I narrow it down a bit.

What do you guys think? For my wheels to rub less what size should I switch to?

Chiragp · #7 04-07-2003, 01:55 AM

Well, looking at everything, it looks like your wheels are rubbing due to improper offset. You have the correct sized tires. Going narrower will force you to stay with 225/45/18s which leave very limited choices, all of which I doubt will be more affordable. Only the $250 Michelin Pilot might be quiter.

Most SL take a low offset to begin with. Find out what the offset of the wheel is. I'm willing to bet you probably got a higher offset (more inward then towards the fender) because the SLs are one of the fewer vehicles mercedes makes that require some of the more lower offsets. Maybe your answer to the question might be hub-centric Spacers (If hate spacers, but if you are going to use them...have to be hub-centric) to compensate for the high offset. This would be the best alternative besides getting proper wheels.

Then you go go with 245/40/18s, and you should not rub. (make sure shocks/struts are not worn....that will do it too.) A good tire for a great price, with great reviews has just came out recently:

ContiExtreme Contact

Price is good too, about $130 compared to $128 Kumhos. Not only that, these are All-season, rated quieter, and better ride...and last longer.

Hope that helps.

spinedoc · #8 04-07-2003, 03:20 PM

I think the offset on the rims is 35mm, but Im not entirely sure. They are mostly rubbing on the inside of the fender lip. I have bent the lips back and they only rub on deep potholes and reversing with the wheels locked.

From what I understand I need more sidewall for a more comfortable ride, and I should consider narrower for less fender lip contact. But Im really bad with sizes and am not sure what to get. Additionally if I get more sidewall, ie: taller tire, I dont want it to start rubbing against the inside of the wheel well.

So in a nutshell I need to go from a 245/40 18 to another 18 inch tire that will be a little more comfortable, but will rub less on the fender lip. For starters I would like some suggestions on what size I should go with, then I can decide what specific brand to go with.

I wanted to order from tirerack but it doesnt look like anyone wants to make the sale...

suginami · #9 04-07-2003, 05:55 PM

Well, my advice is to get new rims that have the correct off-set for the car. Then, you will have a better assortment of tires to choose from.

Chiragp · #10 04-07-2003, 06:54 PM

You can't just go altering tire sizes. It throws of speedometers, ABS, ESP, ASR, or many other things. Going skinnier and smaller so you don't rub will make a tire with a lower load/weight capacity rating.

In short try http://paspeedo.com/calculator.htm and put in the stock size for your car, 225/55/16. Enter 245/40/18 and you will notice a very good match. But anything +/- 0.4" or 2.5% is not recommended.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2409976831&category=38662

You will notice these 17x8.25" come with 245/45/17s. Thats oem. Most 18s come with even lower offsets then 35 for anything wider then 8.5" rims. If the SL is lowered please share, as I can't seem to understand why they rub.

spinedoc · #11 04-07-2003, 09:34 PM

OK that makes sense. I will try and attack this from another angle. I think I finally found a shop that will roll the fenders in for me.

I will go with the 240/45 18's. So far the top contender is the Yoko ES100. I hope its a quiet tire, Im very sick of my current Kumho's. Any further suggestions in the $170 and below range?

Chiragp · #12 04-08-2003, 01:10 PM

Look at my post above the last one....The new Continental ContiExtreme Contacts have a great rating. Right at the top of the list. and at $130, really cheap. It wil last longer then those Kumho and ES100. Look at all the tires in this category:

http://www.tirerack.com/tires/surveyresults/uhpas.jsp

Notice the ratings next to the Michelin Pilot A/S and the next value brand recommendation: the Sumitomo HTR+.

spinedoc · #13 04-08-2003, 07:36 PM

Well Ive been browsing the internet and I am finding some bad reviews on the longevity of the conti's and the noisy ride. Until I find someone with a 500SL and some mileage on these conti's I dont think I will trust them.

The Yoko ES100 are not made anymore, my tire dealer called Yoko. I ordered a set of Yoko DB S2, but my dealer hasnt told me how much, so if they are too much I will prob go for the Sumitomo HTRZ2, for the price I can afford to change them once every 2 seasons.

I really thought of going with a high perf all season tire, but I have heard from too many people that you really do give up handling and traction. I dont drive my SL in the snow, thats what the jeep is for, so Im happy with nice rain performance.

Chiragp · #14 04-09-2003, 12:59 AM

Finding on review of a continental and holding them against all continentals is like saying Mercedes has the worse reliability just because you have one experience with an early-built M-Class.

The new ones are rather nice. But good luck anyways. Charlie.