christopherw

I pumped my tires to 34 and have 32,000 on them, 5mm tread left.

mdadgar

Think that has anything to do with the fact that much of the Autobahn has no speed limits? People cruise at 100 mph over there.

That's, umm, rarer here.

Let's face it, most of what people get with upgraded tires in the US is more high speed lateral grip. That's awesome 2 days per year on your 911 Turbo, but a lot less interesting on, well, everything else.

- Mark, has some experience in this area

Brocktoon

That is a bit of a myth. It is, if anything rarer over there. I spend a good portion of my year in Europe, and most of the unlimited roads are gone, if they are around, in daylight hours congestion is so high you are not moving any faster than an interstate. Most highways are limited to 100km/h or 120km/h which is lower than 75mph. Nine times out of ten, the road will be clogged with Dutch tourists towing trailers, which are limited to 80km/h or 50mph.

I have been around high performance cars and mortorsport my entire life, and that is not what I'm suggesting. I'm saying the GL needs a good, high quality touring tire built on a good, carcass. The GL is no some solid axle Tahoe, or front-drive trailing arm minivan. It is a heavy "car" with very aggressive suspension geometry and piles of torque. I have driven lots of cars, and on lots of tires, but I can tell you there is nothing quite as bad as a BMW three series on a set of Sears Roadhandlers, just as a Dodge Dynasty on Goodyear Gatorbacks will suck.

They are both Sedans, and maybe just used to go down to Safeway. Their use and form is irrelevant, it is what the car is set up to use. The GL is designed with the supposition that a high quality touring tire or performance tire be used. How can I tell? Again, just look at the rear camber, that's your first hint.

mdadgar

Agreed. But the tires are built to take it. TUV has higher standards than DOT in this regard.

And where did I disagree with this? What I basically said was that there's no need for for an ultra-high performance summer tire and used the example of how they were wasted on my old 5-series.

Yes.

BTW, my current Escalade has more torque than any of the GLs and is basically a "solid axle Tahoe."

I think you're missing an important point: there are two things that determine the performance level and expense of the tire: carcass construction and rubber formulation. Much of the expense of a high-end performance tire is in the softer rubber used. The GL doesn't need this and you'll just be burning expensive rubber off as you turn into the Safeway parking lot. And then you'll be pissed because the tires lasted 11K miles.

We agree on the carcass design.

- Mark

Brocktoon

Look, I can tell you are a good guy and for the most part know what you are talking about. I don't pretend to know everything either, but I do have a pretty solid interest in tires, and from my experience, have learned a lot over the years.

You are totally correct about your car's suspension. You have what, 415 lb/ft? GL 420 has 515 lb/ft, the lowly US 320s and 350s have 398-400 depending on the year so it is similar, anyhow, but that is beside the point.

A solid axle works fine in the Escalade, and you could likely get away with more of an LT style tire because of it, because it is, after all a light truck platform. Because of this, the suspension hard points are for the most part carried over from a Silverado, and by their hauling nature, they don't introduce excessive camber into the suspension.

The independent suspension on the GL is a different story. There is a reason the GL has posted the fastest slalom times on any full sized truck in several publications, and that only comes from the suspension. Because, after all, you are dealing with four wheels in similar places, carrying around similar weight.

Keeping things simple, lets just stick to the rear suspension. The GL, like your wife's 5 has a considerable amount of camber dialed in. What this means is that the truck is basically riding around with all the rear axle weight on the inside edge of the tire. When you turn, the inside tire then become more perpendicular to the road, and of course you can figure out what that means. The exact opposite wants to happen on a solid axle. By nature, tires optimized for one, won't be ideal on the other.

Knowing all of this, I would without a doubt expect tires on an Escalade to last longer than a GL. The GL's suspension has the most even contact patch on the loaded wheels when turning, the Escalade, when going straight. I don't know about you, but I spend more time going straight.

As far as I'm concerned, you go into this type car knowing that tire wear will be worse than other cars. As you can see, it is the nature of the beast, as they say.

mdadgar

No. GL420 has 339 lb-ft. GL550 has 391 lb-ft. Per MBUSA.com.

The solid axle is a POS in the Escalade. It's awful.

No, it comes from a bunch of things, suspension included. It also comes from a stiff unibody, which allows the suspension to work better (and to run softer springs, too, all else being equal). It comes from reasonably sticky tires. It comes from lower weight than some of its ladder-frame competitors. And it comes from very good stability control software.

I think you're really oversimplifying, but the reality is that we have very different beliefs on this stuff.

So let's just agree to disagree unless we ever meet in person, at which point we can argue about it for hours over a beer or three.

- Mark

Brocktoon

Fair enough, but you are certainly not correct about those torque figures.

I think you have the 450 confused with the 420, and the 550 confused with the 350. I don't even think they sell the 420 down there so you may want to check out Mercedes UK or something.

mdadgar

No, I was listing the torque figures for the 450 (gas) and 550 (gas) as those, along with the 350 (diesel, 400 lb-ft) are what's sold here in the US.

But my apologies, I read your GL 420 as a typo on GL 450 (and replicated it myself!), since we don't get the 420 diesel in the US and I had forgotten that you're in Canada.

- Mark

Brocktoon

No probs, dude!