Tires, Brakes and Suspension

Gerrett:

What tires did you end up installing on your 600 SWB ? I am over the 10 year mark so time is getting short for my 600 before they need replacing !!

Luis:

Overall, I find nothing bad about Kumhos.. I'm on probably my 6th set between all my cars. The 6.9 has Kumho Ecsta summer tires on it. The only negative about them is they get flat spots immediately upon parking that require about 20 miles to smooth out.

As for the 600 tires, I'd buy the Kumhos in a second if the whitewall was wider.

Gerrett Conover,
M-100 Membership Sec'y
-----------------------
1971 600 SWB
1979 450SEL 6.9
1981 250 LWB
1995 Impala SS
2000 S500
[img=left]http://www.600swb.com/Images/600_sm.jpg[/img=left]

Kumhos are great and very affordable. No problems at all with them. Pretty nice as far as road noise. Had them on two SWB's and a LWB I drove.

Luis

quote:

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Originally posted by Gerrett

Has anyone purchased either of the following tires for a 600?

• American Classic P235/75R15 w/1.6" whitewall
• Kumho Solus KR21 235/75R15 XL

I'm kind of leaning toward the American Classic because of the whitewall size... and it is rated virtually the same as an XL Load tire.

---

I wanted to bump this post from last year.. I said I was going to replace my 600 tires, but I never did, especially since I took my 6.9 to last year's Meet. But the 600 will make its appearance for the first time in a few years at the Florida Meet, so I want to replace the tires. Soooooo.... any opinions on the above??




Gerrett Conover,
M-100 Membership Sec'y
-----------------------
1971 600 SWB
1979 450SEL 6.9
1981 250 LWB
1995 Impala SS
2000 S500
[img=left]http://www.600swb.com/Images/600_sm.jpg[/img=left]

Gerrett,
I have just replaced a set of Kuhmos on the 600., but I don't know if they were the ones you quote and I don't know if Olaf has thrown them out for me to go and check. I can ask if it is important. Looking through some of the photos, the size is the same but they have Power Pr--- in large letters, so perhaps they are different.
Art

I once read somewhere about how the actual circumference of a given tire size can vary quite a lot between different brands and models. This is especially important with 4 wheel drive vehicles, where having all four tires the exact same size can be critical for avoiding differential wear. The mounted circumference also changes somewhat depending on the width of the rim it's on. Obviously, tire pressure is important too.

Has anyone purchased either of the following tires for a 600?

• American Classic P235/75R15 w/1.6" whitewall
• Kumho Solus KR21 235/75R15 XL

I'm kind of leaning toward the American Classic because of the whitewall size... and it is rated virtually the same as an XL Load tire.

Gerrett Conover,
M-100 Membership Sec'y
-----------------------
1971 600 SWB
1979 450SEL 6.9
1981 250 LWB
1995 Impala SS
1996 S500
[img=left]http://www.600swb.com/Images/600_sm.jpg[/img=left]

I completely agree that the first consideration has to be that the tire is safe for the application. But a lot of us nut cases (and I am at the front of the line) are fascinated by, and strive to achieve, the high standards the 600 set from the beginning.

I think it is true that even Mercedes tolerated a fair amount of error in their speedometers, except in the 600. Five percent errors were not uncommon, and road tests by a variety of automotive publications provided the true and the indicated speed at a broad range of speeds as part of their reviews of any given car. Road & Track was the premier of the publications in the U.S.

The 600 was the odd car out in this aspect. As tested, the indicated speed matched the true speed at all measurement points. The measurement points were 30, 40, 60, 80 and 100 MPH. The error was 0%. Simply amazing. Obviously as the tires wore down some error would have to be introduced, but the the fact that the speedometer indicated correctly at any point in the life of the tires was significant. It is also my opinion that allowing the speedometer to read high by X% was targeted at the fact that the speedometer would progressively read faster and faster as the tires wore. Starting with a speedometer that was some percentage fast with new tires would not be a good thing.

Whether it was just luck (not a principle relied upon by Mercedes) or by design, the 600 achieved a goal not readily obtained. If it was important to them, it is important to me, even if, in the grand scheme, it really isn't important at all. We must use the best tires we can get, but if there is one that better matches the original size, that's the one I want. It's a personal thing.

Chris Johnson
www.300SE.org

In my opinion the problems with inaccurate speedometer readings are often overstated and nothing to be really concerned about.

The speed is with these old-fashioned mechanic devices always a kind of educated guess, influenced by a lot of factors. Please have in mind that all speedometers suggest a higher speed than the acutal speed is. A speedometer may never show a lower speed than the actual speed is in reality.

For automobiles until modelyear 1994 the rule is - at least in Germany - a tolerance of + 7 %, for later models + 4 % of the scale is acceptable. This means for the 600 with a scale up to 240 km/h that the tolerance is + 16,8 km/h or in other terms: if we assume a real speed of 100 km/h, the speedometer may indicate up to 116,8 km/h without being considered outside the tolerance.

In theory the speedometer reading with 235/70 R15 tires in comparision with 235/75 R15 tires is approx. 3.3 % higher. For details check out http://www.7-forum.com/service/reifenrechner.php ,the one and only site I know, which takes into account the dynamic effects of the weight lasting on the tires. This effect is responsible for approx. 3 %! Unfortunately the site is in German only.

So DaimlerChrysler does not require a recalibration of the speedometer when using 235/70 R15 tires, DaimerChrysler seems to assume, that the tolerance requirement is still met.

If we do the math, it is clear for me why DaimlerChrysler does not require or recommend a recalibration. Your 235/75 R15 is approx. 1 % smaller than the 225 HR 15, the 235/70 R15 a little more than 4 %. So this is nothing to worry about.

For me much more important is the issue of the availability of reliable tires on an acceptable price level. 235/70 R15 is a pretty common size in our days which is available from all premium brands with a moderate price tag. With 235/75 R15 things look a little bit different at least in Europe. Choises are very limited. All M-100 cars are really heavy, fast and expensive. So they deserve premium tires as well. That is the reason I would never consider an actual Fulda tire for a 6.3 oder 6.9 as discussed in another thread in this forum. Fulda tires of the 60' and Fulda tires for passenger cars today cannot be compared. But this is another story.

Aggie, what does the 235/70 x 15 tire size do to the accuracy of the speedometer? I have the 235s on my 600, but in the 75 series radial, and this causes the speedometer to read higher than actual speed. I believe the 70 series radial would incrase the speedometer error even more.

Joe Edone
1972 600 SWB

DaimlerChrysler recommends as an alternative size for the 600 SWB only the use of 235/70 R 15 tires, which are available from various sources. The tire pressure is altered to 2,4 bar (front) / 2,6 bar (rear) and 2,6 bar (front) / 2,8 bar (rear).

Dunlap ww 255/70 15s on the 1972 Coppola pullman.

1972 600 SWB
1985 300CD
1997 993TT

I had a set of Kumhos on my Cadillac Eldorado (weighs over 5200lbs) and they were terrific. They are the same size and required rating as a 600. Would have gone with Michelins (it's a habit), but I was in the middle of nowhere in New Mexico and one of the front tires delaminated. The tires on the car were practically new mileage-wise, but they were years old and hadn't been used much. I was upset at first to not be able to get Michelins, but it worked out quite well. Those Kumhos laid a pretty mean scratch.

Don't I recall that Karl said you could also put 255/70s on a 600? I swear that's the case. I forget who makes the tire, but I'm almost sure he said that.

Peter in St. Louis

The vintage Michelin tires are XVS, size 237/70 HR 15. One of my 600 has this tires and they work well. But the size is not 100% correct (235/80 was the original...).

Regards
Giovanni
Italy

quote:

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Originally posted by Chris Johnson

Hello Art,

Do you recall what the model of the Michelins were?

Thanks!

---

Art:

My first set were the XA4's, too, on Karl's rec. I didn't like the look of them, so I had a 'custom' set made to the original '71 whitewall spec - which placed the whitewall much closer to the wheel than current tires.

However, I MUCH prefer the 'old school' wide whitewalls, like the (*sniff sniff*) defunct Firestone 721, with the 2" whitewall. Those looked SOOOO good on my Cadillac limo, which shared the tire size with the 600. I don't think you can get those anywhere without getting them made, which I probably will do at some point.

RE: Kumhos... I got my first set on a BMW Z3 about 6 years ago (the OE tire was a Michelin Pilot). WHAT A DIFFERENCE! I have always found Michelins to be HARD tires, and not particularly sticky for my tastes. The Kumhos were a HUGE improvement, for less than 1/2 the cost of the Pilots. I put a set on my Impala SS, but in that case, the OE BFGoodrich Comp T/A's were superior. However, the only Kumhos in the size I needed (25560R17, I think) were SUV tires. Probably a tactical error on my part, there! BTW, when the Impala came out, it used a tire size EXCLUSIVE to that car. Which meant that the tire dealer required your VIN before he would order the Comp T/A's, since they were in short supply (17" tires were kind of a novelty in '95).

Anyway, if Kumho makes an extended load touring tire in a 225/235 15" size, I'd certainly try it!

Gerrett

Chris,
I couldn't when I typed the reply, but today I have the time to pull the invoice from 23 June 1989 and they were 235/75 X 15 XA4's and they were A$249 each way back then. Of interest, and never noticed before, is an ad for KUMHO tyres on the invoice. Strange coincidence!
Art

How about these?
[url][/url]http://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=XW4&vehicleSearch=false&partnum=375R5XW4OWLXL&fromCompare1=yes&place=9

Hello Art,

Do you recall what the model of the Michelins were?

Thanks!

NO doubt there is a car wrecker in Europe who will be dissapointed to hear that you chucked out a unused Dunlop spare....Right Marc?[;)]

Chris,
I've had #178 for 20 years. When I bought it, it had Bridgestone 1 inch strip whitewalls. I could never get them to balance. They flat spotted when the car stood. I tried every type of balancing to no avail. I even had the wheels balanced. The guys at the wheel shop all got together to look at the wheels because they said they had not seen wheels of that quality in years. They said there was nothing wrong with the wheels.

So, even though the Bridgestones had tons of tread, I threw them away and bought Michelin 235/75 R 15 1" thin whitewalls which totally solved the problem. They were hard to get but I eventually got them from a tyre dealer who had a number of Rolls Royce customers as they used the same tyre. When they started to do the same thing, I replaced them with the current set which are Kumho (Korean I believe) P235/75 R 15 105T M+S 1" thin whitewalls which were a much lower price and more readilly available at the time than the Michelins

The Kumho tyres have been very satisfactory. I would add a couple of other comments. For the average 600, the tyres become unserviceable not because of tread wear, but because of hardening with age, making them dangerous for high speed work. Secondly, when I bought the car, it still had the original 1965 (Dunlop crossply as I recall) nylon belted spare tyre in the boot (trunk)!! It had never been on the car and still had those little rubber bristles on the face of the tread that new tyres have and was spotless, again with a 1" narrow whitewall. I replaced it with a new tyre but kept it as a keepsake for a few years but have since thrown it out.
Art