19" vs 20" ride quality - tossing run flats
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Joined: Apr 2007
Posts: 97
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From: Doylestown (Bucks County) PA
2015 ML250, 06 E320 CDI, 2008 GL320 (sold)
19" vs 20" ride quality - tossing run flats
I have a 2015 ML Bluetec with 19" run flats (or think they are run flats). The car only has 38K on them and you have to brace yourself for bumps in the road. Very harsh ride. The tires are Bridgestone Dueler H/L 400 and are the original tires.
I bought the car 2 months ago and love the diesel but the ride quality is poor. Car handles well on turns for a heavy car.
Rims are scraped up a bit so looking for replacement rims and found some take offs but they are 20". I will put snows on the 19" for winter use in Vermont.
Is it a mistake to get 20"? I keep telling my wife that the ride will improve on her car when we replace the run flats. BTW, there is a spare in the trunk.
This will be a perfect car if I can fix the ride quality!
Thanks for the thoughts and advice.
I bought the car 2 months ago and love the diesel but the ride quality is poor. Car handles well on turns for a heavy car.
Rims are scraped up a bit so looking for replacement rims and found some take offs but they are 20". I will put snows on the 19" for winter use in Vermont.
Is it a mistake to get 20"? I keep telling my wife that the ride will improve on her car when we replace the run flats. BTW, there is a spare in the trunk.
This will be a perfect car if I can fix the ride quality!
Thanks for the thoughts and advice.
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Joined: Apr 2016
Posts: 889
Likes: 148
From: Southern Illinois
, 2023 BMW X4, 1991 190E
I do not have Bluetec but the standard ML350 gas. On the gas mL the spare is located under the cargo floor, but yours being a Bluetec, I think that's where the DEF tank is. You will need to do a search on that. Some ML which have the very expensive sound system ( not HK or standard system) have part of the sound system where the spare tire goes. These cars normally have a emergency kit which includes a pump and some sealant. Yours probably does. But again, I have limited knowledge on Bluetec.
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.As far as the ride quality, you will find many post on this site of how bouncy the ML ride is. Thats the nature of the car. Some people go to larger size tire, replace shocks/struts with Bilsteins or put lower springs(H&R) on the car.
With this having the original miles and being 2015. First you definitely need to replace the tires then see how the ride is. (You can look on the side wall of the tires on the car and they will say is they are runflats). Going from 19 to 20 inch wheel will improve handling (going around curves) but will give a firmer ride (less bouncy) than 19 due to the 20 having less sidewall to absorb bumps.
Do a search and you will find a lot of info on ride, suspension etc.
Good luck.
I just did a search "spare tire on Bluetec" and saw a lot of info go there and it should answer your question. I
.
.As far as the ride quality, you will find many post on this site of how bouncy the ML ride is. Thats the nature of the car. Some people go to larger size tire, replace shocks/struts with Bilsteins or put lower springs(H&R) on the car.
With this having the original miles and being 2015. First you definitely need to replace the tires then see how the ride is. (You can look on the side wall of the tires on the car and they will say is they are runflats). Going from 19 to 20 inch wheel will improve handling (going around curves) but will give a firmer ride (less bouncy) than 19 due to the 20 having less sidewall to absorb bumps.
Do a search and you will find a lot of info on ride, suspension etc.
Good luck.
I just did a search "spare tire on Bluetec" and saw a lot of info go there and it should answer your question. I
Last edited by Isawelvis; Aug 25, 2021 at 11:49 AM. Reason: new info
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Joined: Jan 2013
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From: The Great White North
W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
If the Bridgestones are run flats, that is 99% of your problem right there. And, I can guarantee you they are not the OEM tires. The very reason you have a spare is so you don't have to compromise on the ride quality with run flats.
A larger wheel means a lower profile tire and thus less sidewall, so all other things being equal, the ride comfort when going from a 19" wheel to a 20" wheel would theoretically decrease, but in practice on the ML where you have a lot of tire sidewall in either case it is imperceptible. I also use my OEM 19s with dedicated winters and have a set of quality aftermarket 20s with dedicated summers. The summers definitely handle better, but I wouldn't call the ride more comfortable although it is certainly not more jarring either. Buy the 20s for your summers and two sets of quality Michelins (for your winters and summers) and you'll fall in love with the truck.
A larger wheel means a lower profile tire and thus less sidewall, so all other things being equal, the ride comfort when going from a 19" wheel to a 20" wheel would theoretically decrease, but in practice on the ML where you have a lot of tire sidewall in either case it is imperceptible. I also use my OEM 19s with dedicated winters and have a set of quality aftermarket 20s with dedicated summers. The summers definitely handle better, but I wouldn't call the ride more comfortable although it is certainly not more jarring either. Buy the 20s for your summers and two sets of quality Michelins (for your winters and summers) and you'll fall in love with the truck.
