greetings to all,
I am new to this forum and greatly appreciate the points of view and advice given with a high signal to noise ratio.
For a little background, I drive a CLS55 AMG recently aquired and loving it coming from a 2003 bmw 540i Msport which is also a terrific car.
It is now past time to replace the wife and family vehicle which is a bmw X5 4.6is that has been excellent except for in new york snow where its 20 inch wheels and essentially hiperf summer tires are embarrasingly useless.
this has left a strong impression on my wife who will drive this suv 90% of the time and insists that the next suv have allseason tires in a practical size.
as an automotive enthusiast, i know that the smartest solution is a set of winter wheels/tires but my wife refuses this for storage & clutter & hassle of changeover reasons.
i have had my eye on the GL450 for awhile but have been holding out for the GL550. the GL has the room we need that the X5 does not and while the GL450 has pretty good pick up, it is not in the 0-60 in 6.2 range of the hi po X5.
well the GL550 is finally available and comes standard with the 21" wheels. this is a dealbreaker for me. i have explained to my wife that they are allseason and not summer tires like the X5 and that they are only 275/50s and not 315/35s like the X5 rears but she is not persuaded.
i have spoken with one dealer and have been told there is no delete option on the 21"s and they will not swap them for 19"s.
any advice is appreciated (and yes, the wife is a definite keeper!)
do you think that the GL450 all season 275/55-19s would be noticeably better in snow than the 275/50-21s?
(in a worst case scenario, at least there are winter tires in the 19" size but no one makes them in 21")
if i found someone with 19"s on a GL450 willing to swap, do you think that the GL 550 would look okay with 19"s given the stuck on fender flares? will it ride similarly? i am sure that i will take a hit on eventual resale/trade in when some one see the GL550 with only 19"s.
thanks for your time and like sraj,emayer and waitng-4-550, i also play the poor Dr. needing to get to my patients and ER on call rain or shine but for shine ,I take the CLS55 and for snow, I take an old Audi awd with Conti extreme contacts that goes through it all.

 

I know you're looking for opinions, so here's mine...just go with the 21's from the factory and don't look back...the all-season or even summer's should do fine in inclement weather (reason I say this is b/c of the AWD)...will the 550 looks stupid on 19's? No, they'll look just like they did if they were on a 450...I dont think you'll get any complaints on ride quality, but we wont know til we get one in stock and are able to drive it...

 

I will do you one better... I will give you my 18 inch wheels and tires for your 21 inch wheels and tires...

 

The 21" tires on the Gl550 are 295/40 R21 All Season. Whether this helps or hurts your position I don't know...:-)

 

Check this thread (a long one) and there is a picture of the GL550 tire marking. Post #217

https://mbworld.org/forums/showthrea...=191472&page=5

 

Darn it, Dan beat me to the offer of exchange Tell you what, Jonathan, I will even pay for shipping both ways.

So you get to keep the wife and get 18' wheels with All Season tires.

 

I don't think changing wheels on GL 550 will make the wife a better driver....

 

I will ship you a brand new set of 19's and pay for the shipping both ways.

 

They are wide lo profiles, if you hit a few inches of snow or ice, forget about it, it is going to be scary--even with AWD. If you need to tackle hills, scaary. Get 18-19" winter setup. I know, I had 20 inch wide all season pirelli's on my wife's gx470, they sucked. Once i went down to 17s w/ less width and profile, rode like a sleigh.

 

Okay... here comes my ignorance relative to tires. My rep is telling me I shouldn't worry about the 21's, GLFahrer indicated in an earlier post that that the 21's are M+S rated. But, reading the on-going dialogue about the 550's 21" tires, I don't understand why folks believe these tires are going to be such an issue in snow.

As you all know, I live in Colorado, up in the foothills where we get a ton of snow. So, can someone knowledgeable take the time to educate me on why the 21's are going to be such a nightmare? As much as I want the bigger engine and design elements of the 550, I don't want to look goofy in an SUV if I'm going to truly need to run 18" or 19" winter tires for nearly 7 months of the year.

Thanks for the help!

 

I bet you money Boxboss would know. Where are you, boss?

 

It has to do with total surface area that the wheel covers on the ground and pounds per square inch. If you have two vehicle with the same weight but one has the 295 tire and the other has a 265 tire, the vehicle with the 295 tire will have less pounds per square inch than the 265 tire because the 295 tire has more square inches of surface touching the road. This means it is distributing the vehicles weight over more area. In snow you want to be able to have the car put enough pressure on the snow so that the tire gets a grip; if there is not enough pressure, the tires will spin.

The Viet Cong discovered this principal during the Viet Nam War. They initially put their mines in places where the US tanks would drive and set the fuze setting to real high. The mines never exploded because the tank's tread distributed the tank's weight to a very low pressure per square inch. But the VC were quick learners and corrected their mistake.

 

if you live in snowbelt Colorado, you are going to want a dedicated snow tire/wheel set-up trust me. I live in Long Island NY and two winters ago we got like 4-5 inches of snow and the 20" M + S were squirrelish with AWD GX470 which drives great off-road.

 

Personally, I think the 21" wheels will work fine but if you want to trade, I will trade you my 19" wheels with 275 Continental tires. They have about 3,000 miles on them.

 

Is 47 horsepower that big of a deal to you? If it is not then get a GL450 with 18 or 19 inch wheels loaded up with whatever options you want and live happily ever after. Is it going to be as fast as your old BMW X5 or GL550? No, but it is not going to be that much of a difference.

 

Average first snow is mid-October. Begins snowing in earnest around Thanksgiving, so I'm going to wait-and-see how the 21's perform. If they stink, then I'll switch to smaller tire/wheel package for the winter.

Thanks for all of the input.

 

I have a Premier Edition with the 20" wheels and Michelin Diamaris tires. Don't think for a second that the GL will do fine in the snow just because it has AWD. I drove through the snow once and I will never do it again. Go for the 21" wheels that comes with it but get some dedicated snow tires for the winter.

 

I believe that's your best bet... one set of wheels/tires for summer and a different set for winter.

 

Or move to Southern California

 

New here...

I live in Los Angeles, but love going up in the mountains and deserts with the family. Was dead set on getting an 07 450 w/offroad-ads-locking diffs-skid, 18" wheels, Premium, rear entertainment, multi-contour seats, tow, etc to go explore some jeep trails (easy to medium difficulty) and for snowboarding and road trips...but was too late for an 07 so was planning to order an '08 450 instead... that is until we saw the 550...

That's all it took to change plans and switch to the 550. We love the way it looks, especially with those 21's filling those flares. We could live without the jeep trails we thought especially since punctures might be an issue with the tires on the 450 anyway... but now having to get a set of winter tires...makes us think maybe we should go back 450.

Am I underestimating the 550? From what it sounds like here, the 21s might be plain nasty on snow and ice and I'd hate to have all the Subaru's blow by me as I'm fighting for grip with the 21's on the slippery stuff. Or Maybe we should just breakdown and get a winter set, ...and stick with the 550.

Rob

 

Weclome to the board, Rob. I am not an expert on tires but from what I am reading it seems like that having two sets of tires might be the way to go with 550 if you plan on driving in snow. What aboput using chains on the 21 tires? Is that even possible.

 

oknish, thanks for the welcome.

Don't know either if they make chains for that size tire. I'm curious what the manual says about chains. I know the w211 manual states absolutely no chains for the 18's. The 18's are already a very tight fit and there is barely enough room for the tires on the e-class.

I'm thinking a set of blizzaks or bfg all terrains on 18s. Leaning towards the bfgs since they are a pretty burly tire and good offroad too. bfg makes them in 22" and 20". If they made them for 21's I would probably just use the stock wheels and change the tires.

Will the 18s work on the 550? I don't know if the 450 and the 550 have the same brakes...seems like the 550 would have to have bigger brakes for the added performance and to fill all that space in the 21s...

rob

 

The brakes are probably the same on the 550 and 450. I think the 550 stock tire size is 295/40 R21 which has a diameter of 30.3" which is actually a little less than the 19" 450 stock tires. Probably not quite enough increase in performance to warrant bigger brakes either.
Personally if I were living in a warm climate like you I would go with the 550 and as Oknish concluded, use a second set of winter tires for the nasty stuff on your road trips, those 21's will be like surfboards on the deep stuff. But you could try the stock 21's as a test in some snow first and see how they do and then decide on the winter set.

 

Was thinking more along the lines of inside wheel diameter vs. caliper/rotor diameter fitment issues, but I'm probably worrying about nothing. I agree that the performance difference is minmimal. The weight is about the same so really no need for the bigger brakes.

Will have to give the stock 21's a good thorough test in a big icy snow field.

I'm hoping they work well enough because currently I have three sets of race tires crammed in the garage. I think the forth set of jumbo suv tires will make my wife really happy.

 

Yeah I see what you were saying now as far as appearance of the open spaces surrounding the calipers and inside of rim with the bigger wheels. NJ's side view pic above gives a little hint of that. Good luck with your decision on the tires and keep us posted.