bigwen

Hello everybody, I am planning to get a R350, they have RWD AND 4WD,
Can anyone tells me the pros and cons of the RWD AND 4WD? Which one is better?
Thank you very much

smokersteve

2 wheel is slightly better on mpg.

You can go anywhere on 4 wheel drive as long as your tires have traction.

lkchris

When R-class was first introduced, they were all 4Matic.

When it became obvious they weren't selling well, 2WD was introduced to lower the price.

4Matic is clearly "better" and will surely be so when it comes to resale value.

ejsheltra

The front differential is an open differential (power to a single front wheel)that being opposed to a limited slip (power to both rear wheels evenly split) as in the rear. The front is open so you can turn otherwise the inside tire would be chattering around the corner. So for you 4wd fanatics 4matic is actually three wheeled drive power unless you have installed a locker in the front differential.
To your question of which is better, 4wd is marginally (maybe 1-2mpg) poorer on fuel usage but much more sure footed in inclement weather. It tends to tract staighter when high torgue loads are applied. It will not get you out of a skid any easier and can be more of a challenge because power is going to front and back therefore front tires are rotating at the same speed as the rears. The dynamics of getting out of a four skid with 4wd are a good bit different than two rear drive. you cannot let the wheels free wheel as they will not turn fast enough to get the grip back. You are actually applying power which is the reverse of what would be instinctive which is to back out of the throttle.
Rwd is great for straight line acceleration and powering out of a curve.
If the climate you are in is a northen one go for 4wd or 4matic as the resale will be better and the safety factor in bad weather is equally better ie more sure footedness as there are no wheels dragging in the snow, for example.

JTReeves

I've autocrossed my R500 since summer 2007. I've worn out two sets of tires doing it, the first set of Contis that came with the car, and a set of summer Michelins. When the tires are properly inflated, the car handles superbly under autocross dynamics, i.e., accelerate, brake, turn, accelerate again, brake, turn, accelerate again. Transitions from left to right go smoothly as long as you can find the right speed for the cone spacing.

I didn't know about how the front differential works. I never noticed any tendency for a wheel to lose traction under any conditions. I always seem to have just the traction I need at each corner as I maneuver through the course. This kind of driving can not be duplicated on the road - unless you are trying to keep up with the guy who stole your [insert something you value enough to chase after the thief] or are trying to run away from somebody who wants to do you great bodily harm if they can catch you. Under such circumstances, your tire pressures will not be up to what is necessary to maneuver with the precision of control they'd otherwise have. I run 44 front and 38 rear when racing. With normal pressures, the R understeers in hard turns but maintains traction if you slow enough to maintain a good line through the turn.

I bought a new Volvo S80 T-6 AWD this summer. It is FWD until the fronts lose traction; then the rears get traction. I drive it as if it is full-time AWD by not slowing (much) for corners and almost always accelerating out of corners. I am quite happy with the absence of understeer and the neutrality of the chassis in fast turns.

Just for fun, we visited a Bentley store in High Point, NC this past spring. Every vehicle in the store had AWD, run-flat tires, and 500+ hp. Sadly, the salesman wouldn't let us test drive one.

fstshrk

The vehicle compensates for the open differential by slightly braking the wheel that has lost traction in the front thereby giving you traction effective to a locked front. As long as you don't go offroad this is more traction than anyone needs.

The 4MATIC system is capable of driving on one tire only;i.e. one out of 4 tires having traction. There were some cool videos posted on the MBUSA website demonstrating the 4MATIC under all sorts of difficult conditions.
Even the Land Rover LR3/LR4 don't have a locking front differential. This was an option on the LR3 not sure about the LR4.

califix

I have a R500 and was told I needed my front differential replaced. My car has 57700 miles and I just do routine driving (no hauling, cross country). I have been hearing a dull noise that seems to be coming from my left front tire. I can't really describe the noise well but it sounds like the noise you might hear when you swing a rope really fast and it crescendos and decrescendos. I'm not sure that makes sense. Anyhow, it was thought that it was the bearings on the left but the differential fluid was drained and it was dark and had metal pieces. I've looked at other blogs and noted that small metal pieces are normal. Any thoughts? The fluid was replaced and the noise is still there but the power steering seems easier.

melvinh

I have been hear some weird noise in the front end. It sounds like echo cluncking or metal echo noise. It only happens at lower speed around 45 or lower. One tech say it's something loose. One tech say it's shock or ball joint.

Finally, they took out my front sway bar and link rod and nosie is gone, so the dealer replaced both sway bar and link rods.

Hope this helps.