Does The Mercedes-Benz G550 Professional Have What It Takes To Perform Off-Road? C/D Suspension Test

Hi everyone, I'm Dan Edmonds and this is a Mercedes-Benz G550 G-Wagon and I've been trying to get my hands on one of these, but I've been waiting until I could get the right spec and I think this is it. This has what's called the Professional Package, which gives it a lot of the black trim that you're seeing on the sides. It's got that really beefy roof rack and a massive swing-out spare tire carrier in the back. But the big thing that this has that makes it probably the most off-road capable version of the G-Wagon that you can get in the United States is the 18-inch wheels and Falcon Wildpeak all-terrain tires. That is something that you won't see on a G63. So I'm really excited to take the wheels off, see what the suspension looks like, and then take it in the backyard and put it on my Flex Index ramp to see how well it articulates and measure its RTI score. Well, here's the front suspension of the G-Wagon and it's pretty easy to see the upper control arm or the upper wishbone, whichever you prefer, but down here it's pretty interesting. There is another control arm down there making this a dual control arm, a double wishbone one, but it's a little bit unique. So what we've got here is the familiar anti-dive orientation of the upper control arm in which it slopes down towards the rear so that there is a resistance to brake dive that's kind of built into the geometry itself. Here is the coil spring. It's surrounding this damper here which is, according to the label, made by our friends at Monroe. Here's a glimpse at the lower control arm, but it's really broad. I don't think I've ever seen one quite as wide as this. The dampers right here are adjustable. You can see separate rebound and compression adjustment valves going into the body here, but the shock mounts to this fork which straddles the drive axle up front. We see that a lot. Then back here is a position sensor that all four corners will have to help the adaptive damping system make the right decisions. The thing to look at here is not the stuff in the foreground. It's the breadth of the lower control arm which extends from this forward bushing all the way back to this rear bushing. Now nothing's angled here like we usually see to, you know, convert pothole strikes into inward motion in a bushing. I mean you'll get some of that here, but also this bushing looks like it's meant to displace and absorb that in a longitudinal sense. Here's the stabilizer bar bushing here and drop link to connect to the lower control arm there. I have to say that this particular car exhibits a lot of body roll on the skid pad, so I have to think that what we're looking at is a stabilizer bar that's compromised in its ability to suppress roll so that there can be some articulation off-road. Hopefully we'll get to see if that actually pans out a little later. Of course the G-Wagon, you could tell by looking at it frankly, is a body-on-frame SUV in the traditional sense, and if you needed any confirmation of that, well here's the frame. And this little weldment here that's attached to it is where the lower control arm's rear bushing attaches. This control arm isn't terribly long, and this is the outer ball joint and the inner pivot somewhere in here behind the shield, so it's not like this is a real long travel setup. And then if you look, this motion ratio for the coilover is maybe 60% of the way out, so that's not a terribly advantageous motion ratio. But if you line up back here, the stabilizer bar is maybe about here, so that's maybe 55% or 50%, so the stabilizer bar diameter that we saw isn't going to be as effective as you might think that thickness would produce, which when you're trying to have articulation off-road isn't a bad thing. What we haven't seen is any of the steering stops in here where the hub and the lower control arm meet to take the stress off of the internals here when you reach full lock. So perhaps this rack has been beefed up internally where we can't see it to take on that responsibility. So the front brakes has two piston sliding calipers. You can see these two lumps are where the pistons are. There's no pistons on this side. The caliper here floats on the pins that are represented by this bolt and one just like it at the bottom. It's kind of like your hands. If you pick something up like this, you know, you're only applying pressure on this side, but you're squeezing it against this side, so that's how a caliper like this can clamp both sides with pistons just on one side. And of course it's a ventilated rotor, and you saw these lug bolts, which Mercedes likes to use. They thread into holes here, and you can hang the wheel on this while you're trying to get these started. And as long as the wheel is balanced as far as on this lip and it doesn't have too much weight like real deep dish wheels might have, that actually works pretty well. Well that about sums up this look at the front suspension of the G550 G-Wagon. I'm going to put this front tire back on and move to the back and see what's going on at the rear. So here we are at the back at the G550, and you know it's a solid rear axle which befits an off-road vehicle with a ladder frame. So yeah, Jeep Wranglers have this set up with coil springs and links locating the axle. The 4Runner's like that. Land Cruiser's been like that. Any number of off-road vehicles. The familiar aspects are we've got an upper and lower trailing link on this side and the other, so that's four, and then the fifth link, because sometimes this is called five-link suspension, is a lateral panhard bar, track rod, mix and match those terms however you want, but that's the fifth link. And of course here is the coil spring, and I've got another aluminum-bodied Monroe adaptive damper. What I don't see is a rear stabilizer bar, and that may account for some of the excessive roll, I would say, on the skid pad, but it also points towards a potential decent articulation score. So we'll have to see if that holds true. So here are the two trailing links on this side, the upper one and of course the lower. This one is shorter than the one at the bottom, especially at the front end, and so that will alter the nose of the diff as this moves up. There'll be a little bit of twist to it, and that's to keep the universal joints in good alignment throughout the range of suspension travel. Here's the coil spring, and right here in the middle is a bump rubber, and so you'll get a certain spring rate until the bump stop hits, and then it'll stiffen up until the bump stop fully compresses, but that'll be a gradual process so it doesn't crash the bump stops. A couple things to note here, here's another one of the suspension position sensors like we saw in the front. All four corners will have those, so the adaptive suspension can make the right decisions, but also right here, that is the exhaust pipe exit. You know, on an AMG, they're out here where they could get crushed on a rock. Well, that's kind of protected underneath there, and I guess the cabin is sealed up so that at idle, waiting to pick up your kids, you're not going to get carbon monoxide or whatever in the cabin. But that's interesting because that definitely protects it from trail damage. So here's the rear damper, and of course we can see the two wires going into the two valves, one for rebound, one for compression, and it mounts to this little bracket here that's right on the end of the axle, so it's pretty close to a one-to-one motion ratio. You know, with solid axles, if both sides are going up at the same time, everything's one-to-one. It's when you get into roll where the inboard placement starts to matter. So anyway, that's pretty far outboard and also very well protected up against the wheel and tire assembly. Still, these are down here in a somewhat vulnerable position, so you still want to be careful and know what you got back here. I wish they were inverted, frankly, because if they were inverted, not only would we get the unsprung mass benefit of just having the shaft down here, but that would put all this stuff up high where nothing can touch it. So here's the panhard bar, aka track rod, and that end is bolted to a bracket that's part of the axle, and this end is bolted to a bracket that comes down from the frame. So yeah, that keeps the axle from moving sideways, and this is the missing fifth link in a five-link suspension. Now, one thing you've noticed about G-Wagons is they have their spare tires mounted in back. That's not just a styling affectation. It's necessary because the distance from here to here, the rear overhang, is really short. There's no way you're getting a tire in here, and so it's on the back instead. That's great for off-roading, though. We like short rear overhangs. They help with the truly off-road appropriate footwear, and that means this is an 18-inch wheel, and we have a good amount of sidewall. You know, off-roading on dubs is just dumb. Anyhow, these are 26560R18 Wildpeak AT, and there's a whole lot of other letters here. AT3WA. Anyway, they're Wildpeaks made by Falcon, and they're on this 18-inch wheel. Let's see what it weighs. 69.4 pounds, and of course, there are five of these because the spare tire carrier has another matching one just like it. Well, that's it for the close-up look at the suspension of the G550 G-Wagon. The only thing left to do is for me to put this tire on and drive it up my flex index ramp and see if I can get an RTI score for it. You know, considering it doesn't have a rear stabilizer bar and the fact that the front one doesn't prevent a whole lot of body roll on the skid pad, I kind of have high hopes. Let's see if I'm right. Gotta love a four-liter twin-turbo V8, right? Maybe that's it. Let's find out. Well, as you can see, I can lift it up, and that won't go in. But if I lift it up, it will go in, and it won't come out unless I lift it up. So I stopped at the perfect spot. That almost never happens. Well, now we come to the part where I make the measurement. I'm going to put a little extra tape on this glossy paint here so this won't scratch it up as I make my measurement. Luckily, Mercedes has thoughtfully given me a logo that has an exact point in the middle, so it's going to be very easy for me to line this up. That's not always a simple matter with other car logos. All right, that's it. Mark it with tape, and then we'll measure the height off the ground because the ramp doesn't come to a point. And so I can't measure. I really want the amount of climb, but if I measure this height and divide by the sine of 20 degrees, math alert, which is the angle of this ramp, I can then calculate what this distance is. And then I compare this distance to the 113.8-inch wheelbase. I'm going to write that down right now while it's still fresh in my mind. So let's see what we have. That's 19 7 8ths. So 19 7 8ths is 19.875. Divide that by the sine of 20 degrees, and I get a climb distance of 58.1. And I'll just put that right there. And now I'll divide that by the wheelbase, and I get 0.510. And I can see what's going to happen here. I think you can too. Multiply by 1,000, and I get 510.6, which rounds up to 511. So 511 is the flex index score for the G550. Another way to look at this is the climb distance is 51% of the wheelbase of the vehicle. A perfect score of 1,000 is really 100%. That means the rear tire touches the ramp before anything lifts off the ground. And I haven't seen a stock vehicle that can do that yet. So here are the scores of some other off-road SUVs that I've measured. Topping the list is the Toyota Land Cruiser. This is the 200 series, and that has KDSS, so it has automatic disconnecting stabilizer bars. This is the Lexus LX600, which is a 300 series Land Cruiser that Toyota refuses to sell as a Land Cruiser. We're going to get something else. But if you want a 300 series, you can get a Lexus. But these don't have KDSS like this does, but this is still a pretty good number. This is my own Toyota 4Runner with the TRD off-road package and the KDSS option, which is only available on the TRD off-road package. And this is a Land Rover Defender 110. And I think you can see where the G-Wagon is going to slot in. It's going to slot in better than the Defender 110. Not quite up to the same standard as my KDSS-equipped Toyota 4Runner. Frankly, I was hoping for a little bit more, especially considering how much body lean this had on the skid pad and the fact that it doesn't even have a rear stabilizer bar. And the fact that it's a G-Wagon, right? But yeah, it does have triple lockers, though. And triple lockers will allow you to, you know, get through places where one wheel comes off the ground. But you'd rather have all four tires on the ground at all times. So you don't get any teetering over obstacles that could, you know, get you in trouble if it goes too far. And, you know, you'd rather have all four wheels on the ground at all times, which is why I measure it and why I think ramp travel index, flex index is important. Anyway, that's what I think. Let me know what you think in the comments.