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Suspension & Rim Size & tire selection – My experience
I have been reading in this forum a lot about suspension, rim size, and runflat/non-runflat selection, and its impact on comfort ride and performance driving. Let me give you my opinion based on the experience of having been able to thoroughly test different configurations. Here we go.
Suspension type: Standard spring vs Air Suspension (Air Body Control).
The standard spring suspension gives a very good comfortable ride. The main improvements the Air Body Control system provide are: (a) it will control de bouncy sensations from the springs, (b) it will control the car from waggling in the curves, (c) it increases stiffness in Sport/Sport+ mode to increase control in the curves, and (d) it will adapt the height of the vehicle, lowering it in sport/sport+ or increasing it at the touch of a button if you need more clearance in offroad or heavy snow conditions.
If you expect the Air Body Control system to be like “driving on an air bed” then first test drive, because this is not it. If you want the bouncy cushion feeling, then you should go for the springs. In my opinion the Air Body Control system gives much better comfort, as it names describes, by how it controls the body of the vehicle during the ride, especially in curves.
If you mainly drive in the city and do not drive in any curvy roads. Stick to the springs. The Air Body Control excels brilliantly in the mountain curvy roads, but I do not think it provides any benefit in city driving.
Rim Size
I know large rims (20” & 21”) might look cool. But if you do not plan on putting the car in a track, there are only inconveniences: stiffer ride and having to be extra careful with the curbs when parking. There is a very big difference in ride comfort from a 21” compared to a 19”. You will feel every single crack or rock on the street on the 21”.
The only reason for going with the 20” or 21” is aesthetics. I have found that the 19” with normal tires to be the best compromise between comfort and performance. I have pushed my car heavily in mountain roads with the 19” and have not felt any waggle (it is true that I do have the Air Body Control system). If you often drive on offroad conditions you might even want to go down to 18”.
NOTE: These comments are about the MB GLC assuming tire outer diameter to be equal. Therefore the larger the rim, the smaller the section height.
Runflat vs Normal
To make it quick, runflat tires are much stiffer than normal tires. Is this bad? Not if you choose the right rim size. If you have 19” rims with runflat tires, the ride is like that of a 20” on normal tires. So, I really do not want to know what a 21” is like with runflats. I will leave that to those of you that will put the car on a track or want to look extra cool.
My selection:
Configurations tested:
19" Normal + Spring
19" Normal + Air Body Control
19" Runflat + Air Body Control
21" Normal + Air Body Control
20" Normal + Spring
I drive about 20% city, 50% mountain roads, 30% highway. I have a 250D with 19” with normal tires and the Airbody Control System. I have a very nice comfortable ride with incredible high-speed curve control in the mountain roads. I will be switching to a 43AMG in April also with 19" and normal tires. The aesthetics: here’s a photo.
Great write-up, obviously a lot of consideration given to it. We mustn't forget those that it is totally subjective Everyone's experience and reference of what is good will be different.
Thank you SO MUCH for the review. I'd been reading the C class forum to get answers on the air ride and this helps a lot. Just so I have this clear, you are saying the airmatic controls body and secondary motions better so the ride should be more stable and flat, whil actual bump absorption is about the same?
On the topic of RFT, I've learned to just sell the new ones as soon as you get them and put good tires on. If I buy a GLC it will get Michelin Premier LTX as soon as it arrives at the dealer. I'll put together a cheap spare from Tirerack and throw it whenever I drive out of town.
Great post. My GLC43 is approaching delivery. It was custom to order, at the point of order the only locked in option was the 21 inch rims (full titaniums, not the black look ones).
Can anyone who has 21 inch rims share if they find the ride as rough as the poster suggests?
I do love the look and was glad to have this option pre-selected.
Great post. My GLC43 is approaching delivery. It was custom to order, at the point of order the only locked in option was the 21 inch rims (full titaniums, not the black look ones).
Can anyone who has 21 inch rims share if they find the ride as rough as the poster suggests?
I do love the look and was glad to have this option pre-selected.
Nope not rough at all. I find it more compliant than my VW Golf R on 18" wheels, nor my Audi Quattro on 18" wheels. Including crashing into any potholes in the road. I would seriously not be concerned about it at all.
Daniel,
Great write-up. I'm with you on the logic. I went with the standard 19s in the UK. I really like the look (although not a majority view!)- suitably chunky for an SUV and the fatter rears look good. I really don't like the 20s at all (a personal style thing) and although I think the 21s look stunning , I wasn't wholly convinced on replacement cost, comfort and longevity. I've found the ride comfort great although it is firm which I'm happy with.
You might want to check what tyres your 43 comes with. Mine came with Michelin Latitude 3 non-runflat which I'm very happy with - although I suspect due to the crabbing issues on RHD cars. I notice some cars come with Hankook Ventus.
If you don't mind me asking, what roofbars do you have?
Thanks
Gobi
Daniel,
Great write-up. I'm with you on the logic. I went with the standard 19s in the UK. I really like the look (although not a majority view!)- suitably chunky for an SUV and the fatter rears look good. I really don't like the 20s at all (a personal style thing) and although I think the 21s look stunning , I wasn't wholly convinced on replacement cost, comfort and longevity. I've found the ride comfort great although it is firm which I'm happy with.
You might want to check what tyres your 43 comes with. Mine came with Michelin Latitude 3 non-runflat which I'm very happy with - although I suspect due to the crabbing issues on RHD cars. I notice some cars come with Hankook Ventus.
If you don't mind me asking, what roofbars do you have?
Thanks
Gobi
Mine is coming on the standard 19's, if I get chance I will be going to dealers and will have a look what make the tyres are, would be happy with Michelin latitude as I have had them before. Would have ordered larger wheels as in my opinion they look better but was outweighed by comfort and less chance of kerbing.
Daniel,
Great write-up. I'm with you on the logic. I went with the standard 19s in the UK. I really like the look (although not a majority view!)- suitably chunky for an SUV and the fatter rears look good. I really don't like the 20s at all (a personal style thing) and although I think the 21s look stunning , I wasn't wholly convinced on replacement cost, comfort and longevity. I've found the ride comfort great although it is firm which I'm happy with.
You might want to check what tyres your 43 comes with. Mine came with Michelin Latitude 3 non-runflat which I'm very happy with - although I suspect due to the crabbing issues on RHD cars. I notice some cars come with Hankook Ventus.
If you don't mind me asking, what roofbars do you have?
Thanks
Gobi
Hey Gobiman - I've just taken a look at the data in the UK. All GLC43 on 19" that are known to have filled out the crabbing survey have the Michelin tyres.
Kerbing was another issue for me. I tend to park in a square in Central London which, thankfully, has quite low kerbs and the 19s seem to have enough sidewall to clear them. I was also quite keen on the Q car look (I've bebadged) which has the added advantage of making the car less obviously attractive to the tea leafs.
I have winters on now which aren't affected (so far!) - albeit they are run-flats.
I only had the Michelins on for a week back in November when it was pretty warm so haven't fully tested them to be fair, and your data is pretty ominous!
Another thing to consider on 20" or 21" is tire size. If you plan on always replacing tires with OEM at the dealer, you are probably ok. But if you want to go non-OEM the tire selection was the worst I'd ever seen. They are really uncommon size.
Another thing to consider on 20" or 21" is tire size. If you plan on always replacing tires with OEM at the dealer, you are probably ok. But if you want to go non-OEM the tire selection was the worst I'd ever seen. They are really uncommon size.
At first I thought nonsense, but I just went on tirerack and to my surprise it came up with nothing. What on earth is going on in the USA? Why aren't those tyres readily available. Here in Europe it is no issue at all.
BY readily available in Europe you mean in a variety of other brands?
MO Marked tyres always have its limitations. But if you are happy to go for alternatively no MO markings then yes plenty of other brands as well. In 20" 285/40R20 for example shows up 4 different brands and 5 different models. 3 of which are MO marked as well. And that is just the first search.
If I go to the fronts at 255/45R20 then there is too much choice to quickly count
Thank you SO MUCH for the review. I'd been reading the C class forum to get answers on the air ride and this helps a lot. Just so I have this clear, you are saying the airmatic controls body and secondary motions better so the ride should be more stable and flat, whil actual bump absorption is about the same?
On the topic of RFT, I've learned to just sell the new ones as soon as you get them and put good tires on. If I buy a GLC it will get Michelin Premier LTX as soon as it arrives at the dealer. I'll put together a cheap spare from Tirerack and throw it whenever I drive out of town.
Bump absorption is strange with Air Body Control. For example if you go over a road traffic bump it will go over it a bit stiff. I think the springs go over them with more comfort. But then on other situations it will go over other types of bump softer. Haven't really been able to determine when it will go softer or stiffer.
On the other subject do you mean take out runflats and put normal tires? I understand the rims are specific for runflat...
Daniel,
Great write-up. I'm with you on the logic. I went with the standard 19s in the UK. I really like the look (although not a majority view!)- suitably chunky for an SUV and the fatter rears look good. I really don't like the 20s at all (a personal style thing) and although I think the 21s look stunning , I wasn't wholly convinced on replacement cost, comfort and longevity. I've found the ride comfort great although it is firm which I'm happy with.
You might want to check what tyres your 43 comes with. Mine came with Michelin Latitude 3 non-runflat which I'm very happy with - although I suspect due to the crabbing issues on RHD cars. I notice some cars come with Hankook Ventus.
If you don't mind me asking, what roofbars do you have?
Thanks
Gobi
I do not know what tires the new car will come with. All I now is that they will not be runflats.
The bars are THULE standard wingbars. But I have to say they are bit noisy. For the 43AMG I will be getting the Wingbar Edge.
Nope not rough at all. I find it more compliant than my VW Golf R on 18" wheels, nor my Audi Quattro on 18" wheels. Including crashing into any potholes in the road. I would seriously not be concerned about it at all.
Thanks dejongi - this is truly appreciated insight.
On the other subject do you mean take out runflats and put normal tires? I understand the rims are specific for runflat...
Yes. There *shouldn't* be anything special about the rim as far as running non-runflat. I've never heard of such a thing anyway.
My experience with RFT is that you get MORE flats, because they are so prone to pinch flats on the sidewall. I've had two in the last year on my M235 with 18" rims. I can't imagine how the 19" guys do it with those little rubber bands for tires on them. So between that and much degraded performance - at least on BMW models, but so far sounds like everyone has these complaints - I just prefer to put top performing normal tires on right away.
Yes. There *shouldn't* be anything special about the rim as far as running non-runflat. I've never heard of such a thing anyway.
My experience with RFT is that you get MORE flats, because they are so prone to pinch flats on the sidewall. I've had two in the last year on my M235 with 18" rims. I can't imagine how the 19" guys do it with those little rubber bands for tires on them. So between that and much degraded performance - at least on BMW models, but so far sounds like everyone has these complaints - I just prefer to put top performing normal tires on right away.
comparing diameter without stating the width doesn't mean anything unfortunately. Not a huge difference between many when you stay at manufacturers recommended sizes.
None of them are a bad ride. I'd just get the ones you like the look off.
The relevant metric would be sidewall height. And since *typically* the width vs sidewall ratio get jiggered around to maintain the same diameter tire as you go up in wheel size, the net effect is the sidewall tends to get shorter, which can degrade ride quality and cause more pinch flats.
Now maybe MB works some suspension magic to compensate and they ride exactly the same. Awesome. But that would be pretty atypical for what normally happens on most any vehicle when moving between wheel sizes. This is a well understood. Not saying your perception is incorrect, just that if is accurate it would be pretty uncommon.
The relevant metric would be sidewall height. And since *typically* the width vs sidewall ratio get jiggered around to maintain the same diameter tire as you go up in wheel size, the net effect is the sidewall tends to get shorter, which can degrade ride quality and cause more pinch flats.
Now maybe MB works some suspension magic to compensate and they ride exactly the same. Awesome. But that would be pretty atypical for what normally happens on most any vehicle when moving between wheel sizes. This is a well understood. Not saying your perception is incorrect, just that if is accurate it would be pretty uncommon.
my perception is based upon four years of actually owning 21" wheels with airmatic suspension.
my perception is based upon four years of actually owning 21" wheels with airmatic suspension.
I ordered my GLC43 with 21" wheels - I know they are summer tires, but are they also runflats? I asked the dealer and was told they have no way of knowing.
I have runflats for both summer and winter for my current vehicle and don't find the rides uncomfortable at all:
I ordered my GLC43 with 21" wheels - I know they are summer tires, but are they also runflats? I asked the dealer and was told they have no way of knowing.
I have runflats for both summer and winter for my current vehicle and don't find the rides uncomfortable at all:
In the UK they are not run flats. They get delivered with Continental SportContact 5. I do not know what other markets get, but I suspect the same as that seems to be the only brand available with MO marking.
02-12-2017, 06:54 AM
Everyone's experience and reference of what is good will be different.
