What's the difference bet. AWD and 4WD? - PeachParts Mercedes-Benz Forum

DieselHead · #1 04-26-2003, 08:48 PM

Hi,
This is probably a pretty simple question but someone asked me it yesterday and I realized I didn't know. Thanks.

Alex

bobbyv · #2 04-26-2003, 11:12 PM

a 6-wheel all-wheel-drive military truck is not 4WD ...

Kuan · #3 04-27-2003, 08:44 AM

4WD has low range, AWD does not.

Blu 420Sel · #4 04-27-2003, 09:43 AM

I think there is also a difference in the power distribution between front and rear tires. I used to know but I forget..... Awd is more for traction and handling while 4WD is more for offroad applications. A 4WD vehicle can actually pull a car out of a ditch or whatever with just the front wheels catching...

#5 04-27-2003, 10:29 AM

AWD is a reactive system, and can still be part time. AWD vehicles sense which tire is in a low traction situation and transferres power to the ones that have more traction. In the case of my VUE, it is a FWD car untill one or both of the front tires lose traction. The system then comes online and transfers power to the rear. A 4wd system is typically a manually activated system either via a switch or lever. Some of the simpler vehicles will also require you to get out and manually lock the front hubs in order to work correctly. These part time systems cannot be used on hard surfaces as they need to be able to scrub off differences in wheel speed on turns. Using them on hard surfaces will result in a condition called "Axle windup" which can do severe damage to the drivetrain.

DieselHead · #6 04-27-2003, 03:00 PM

Thanks for all the info. So does that mean my landcruiser has AWD? It also has a center locking diff.

Alex

akry · #7 04-27-2003, 04:25 PM

Kuan's answer is the shortest, cleanest answer.... As AWD and 4WD can have any of the mentioned features above, EXCEPT ONE!!! 4WD has Low-Range, and AWD doesn't....

Land Cruiser should be a 4WD as it also has low-range if I am not mistaken.....

akry · #8 04-27-2003, 04:30 PM

Forgot to metion, AWD usually is permanently engaged in AWD mode OR switches between RWD/FWD(depends on design) and AWD automatically w/out driver's input....

4WD usually needs driver's input when changing from 2-wheel-drive to 4-wheel-drive(though there are exceptional, e.g. Jeep Grand Cherokee's Quottra-Drive), but ALL 4WD has driver-select Low-Range, which locks front/center/rear differentials(If applicable).....

#9 04-28-2003, 02:06 PM

Your Landcruiser is 4WD but it is always engaged through a center differential. When in low or with the "center diff lock" button depressed the center diff locks for better traction. Many 4WD vehicles only have a front and rear diff so you drive around town in 2WD and when you need it you shift into 4WD but b/c they don't have a center diff the front and rear axles are locked together so you only want to use it on soft/slippery surfaces like sand/mud/snow/ice. If used on hard surfaces some wheels will need to slip to allow the vehicle to turn and its rough on the mechanicals.

The Landcruiser has the added benefit of having front & rear locking diffs on the 80 series when the going gets rough. If you lock down the front and rear diffs it is extremely difficult to steer b/c all 4 wheels are lock together and there is absolutely no slip to allow for turning. All 4 wheels are getting exactly the same amount of torque. At this point all you need is one wheel with traction to keep moving (in theory)!

The MB G-wagen is similar to the 80 series with a solid front axle and 3 lockable diffs. Either one of these machines is your best bet offroad stock out-of-the-box. The newer Landcruisers (100 series since 1998) use an independent front suspension which is less desirable offroad. In markets other than the US Toyota offers a 105 series which is the newer better 100 series body on top of the older better 80 series suspension with a solid front axle. Best of both worlds but apparently not needed for the US "Mall Cruiser" market.

More than you wanted to know.

Randy
'94 E500
'94 Landcruiser FJZ80
'00 S500

DieselHead · #10 04-28-2003, 04:01 PM

Quote:

More than you wanted to know.

No no, the more the better. I noticed that you have the same 80 series that I have. It was actually my parents' car that we used as a family vacation mobile, and as a hauler for garden stuff, house stuff, etc. My parents liked to do a lot of home stuff their self, save some cash you know? It's a great car and has had NOTHING go wrong in the past 102K miles. There are some minor complaints, like bad gas economy, and slow window motors, but it's been a fantastic car. More than YOU wanted to know.

Thanks for all the responses, I now know what the difference is.

Alex

DieselHead · #11 04-28-2003, 05:54 PM

I have only put on 3K miles since it was given to me by my parents. Most of its time is spent sitting in the drive way and I try not to drive it when I don't have to. It sure does go through pads quickly, the rears much less so than the fronts. When my dad was using the car, I had to change the front pads every 12K to 15K (from around town and "city" driving). I used really soft pads though, as I figured I'd rather change pads often than change the rotors often, although I have done those and they weren't too bad. The car is great, but the brakes are a little too weak for a car that size and weight. Although, I guess it only weighs 4600 or 4800 pounds, which isn't much relative to the weight of some of the new cars. The new Landcruiser is something like 1500 or 2000 lbs. heavier. Outrageous.

Alex