The spare tire also spins with AWD, simple as that :)

Professional KZfaqr and still uses whiteboards for graphics, I love it! Keep things real man!

This whiteboard stand must have been expensive

Finally I can go rock climbing in my M5!

Average engineer: "Simply use AWD for road car and 4WD for offroad car." German engineer: "How about making 4WD more complicated so it can mimic AWD?"

I love this channel and I am so happy to see Jason’s success! I remember him doing videos in his uni bedroom and now he is using an M5 just to hold his whiteboard. Thank you for the content

I'm a simple guy. I see a whiteboard, I press like.

I really enjoy all of your videos for the technical detail you're able to provide in an easy to digest manner. However, as someone big into off road driving, rally or rock crawling, I get especially excited when you upload 4WD related videos. Thanks for all the great vids!

So the M5 has 4WD that mimics AWD? Clever!

Simplicity with using white board makes your explanations simple and clear for viewers Thanks a lot...

*Dude it's easy 4WD uses 4 wheels and AWD uses all the wheels* 😂😂😂

I just spotted this one, and watched it. Good video, and a good attempt to explain the difference between AWD and 4WD. However, several things you said are not quite true" First , no matter what BMW "claims" their X-drive system is, it is, in reality, a selectable AWD system, not a 4wd system. The presence of that clutch pack in the transfer case really turns it into an AWD system when turned on. It's all about marketing really. Second, a 4wd system can absolutely be used on the road in 4H or 4WD without the gearing reduction. There are two great uses for this, snow and rain conditions. On dry pavement, it will still work just find and the amount of bind in the center in minimal. So if you're driving on a paved road with some snow cover, you can use 4H without endangering your driveline, with no need to keep switching the t-case from 2H to 4H and back. $L is for offroad use because it WILL create a lot of bind in the drivetrain if driven on the street. But again, in deep snow it will also work fine. Third, AWD is NOT good for offroad. It actually sucks. Mostly because AWD systems do not have the strength in the driveline components to take on rocks and other high-stress obstacles without snapping. Also, AWD systems often use a vscuous coupling unit for that center differential, which when stressed very hard (as offroad obstacles are wont to do) the coupling unit will slip and overheat the oil in it, possible burning it out. Lastly, AWD systems are not mostly FWD and then they send torque to the rear when needed. Some do that, mostly care that in their non AWD version is a front drive car. If the base model of the AWD car is a RWD car, then usually the AWD version is heavily rear biased AWD. Some thing like a 35:65 torque split (which was the normal split for the Astro Safari minivan's AWD versions). Check out Subaru's AWD system in the Outbacks. Most AWD systems are not one axle gets all the torque until needed, but they have a preset bias. 85:15 is common for cars that are FWD base models. Basically AWD is a street system that provides excellent traction in wet/snowy conditions and great off-the line starts without wheelspin, and 4WD is for offroad performance. Keep up the good videos though, your content is easy to watch and fun.

Thanks for the clarity. 🤝 Keep up the good work! 👍👍

You really broke that down to the simplest form. Great explanation thanks!

Told me exactly what I wanted to know. I was coming across a lot of usage-focused or "which is better" explanations to this question. But this video told me succinctly the gist of what the intrinsic mechanical differences between the two are. Thanks for that!

Love the semantics clear, straight, to the point.

Thanks so much for the video

They might as well make it so the suspension can raise a couple inches or feet so your bmw m5 can be an off road tank

Ya your videos have always been interesting and just cool to watch I enjoy them keep em coming buddy !

Great content. Even better detail of the differences. Yes, I'm subscribing.

The Skyline GT-R has had that since 1989 with the ATTESA E-TS system, only it wasn't user-selectable.

Awesome vid Jason! Closing in on 2M subs!

Great explanation and practical visuals - love it.

This guy has top-list infos! I’d started to watch his vídeos since his 500k or so subscribers. Now he got +2,3mi and demonstrates the same motivation to spread his knowledge. Thank you for sharing...👍. Congrats, from Brazil!😉🍾

My aunt had an awd suv that struggled to get through the driveway when it snowed, because you couldn’t set/select when all the wheels engaged. They would only all engage after the tires started spinning, which made it useless at that point anyways. Since then she’s gotten a select 4wd suv and has no problem.

Great explanation. I was wondering how they did that 4WD drive system. I would imagine it works well to help that car handle amazingly.

Best description video I could find thank you EE!

I just want more on that topic from you! Well explained so far.

How about a video explaining 4WD/AWD systems in transverse engine cars? For example, Mitsubishi Evolution, Golf R, etc.. Awsome video as allways!

WD40 wheel drive

THANK YOU FOR ANSWERING THIS, this is kinda what i thought, lack of a center differential, but it was NEVER clear anywhere i looked this discussion has come up so many times for me and i never had an absolutely certain answer for anyone

Great vid, as usual mate. Cheers from Australia 🇦🇺

Jason the type of guy I can depend on to upload on a Sunday.

Didn't you have a video covering all wheel drive in the 911? You should put that one up there in the description too since that's a bit different with the engine in the rear.(I think you mentioned how it's effectively a rear wheel AWD system that sends power to the front vs most systems which are effectively front wheel that can send power to the rear.)

Interesting subject, thanks for the knowledge!

Love this channel. Explained it well!

10% comments- Thanksgiving 90% comments- *Whiteboard*

All very amazing and expensive when it goes wrong!

Great description!!!

Nice job man. Thorough as usual

I used to have an ‘88 325iX and it used a viscous coupled transfer case. It was completely seamless and its intelligence was in the elegant simplicity of the design. You didn’t need multiple clutch plates or speed sensors, it just used the natural property of the oil to thicken up when there was slippage.

You are not correct on this one. AWD and 4WD are the same thing. The actual terms used for what you're explaining are "Full-time" and "Part-time". A full-time AWD/4WD system is always engaged, powering all the wheels, with a central diff (it could be a simple open diff or a diff with an additional automatic locking mechanism). Some such systems come with a user lockable central diff, like Land Rover Defender and Toyota Land Cruiser; some don't, like a lot of AWD/4WD passenger cars and crossovers. Part-time systems can be engaged and disengaged by the driver, and don't have a central diff. They are usually meant to be driven in 2WD mode on normal roads and the 4WD mode is intended for loose terrains like mud, snow, sand, etc. Examples are the Jeep Wrangler, Toyota Tundra and Hilux. There are part-time vehicles like the BMW shown in the video that can always be driven in 4WD mode but such solutions are not present on all part-time systems. These systems use some sort of an automatic locking mechanism, which could be a clutch, a viscous coupling, etc.

Straightforward simple explanation; thank you.

Man your presentation to explanation to the animation... Just rocks... Instant subscribe... Thanks for the video...

Could a 6 wheel G wagon have 4 wheel drive🤔

More confused at the end than when I started.

Finally, an explanation that makes sense! Thank you so much!

Very cool video (s) . I always find myself learning something new with your presentations

BMW has tons of cool stuff but cant keep seals from leaking after 50k miles

So is awd basically a “smart” form of 4wd?

I love your channel. This is an amazingly great video. Thanks!

Explained perfectly. My dearly departed Dad was the one who explained this "center differential" engineering to me since I was a child.

You did a video on the Ford Raptor yes? That also has a clever drive system

can u explain about the six stroke engine patented by an Keralite. I really don't understand it

Great videos keep em coming!

Jeep did this nearly 20 years ago with a viscous coupling in the transfer case. And my 89 cherokee can be set in 4wd full time which basically makes the tcase an open diff, as well as locked and low range capabilities.

Very educational video. BMW should pay you for this review. lol

One of the problems with computer controlled AWD is that the power transfer can get flaky in conditions not programmed for. I have seen units nearly cause loss of control in a windy mountain road. Nice explanation. Thanks.

Love all your videos

Jason, Never give up the whiteboard. It's just such a part of the channel's charm. It also gives a really unique vibe to the channel. Reviewing high end cars on a white board. Love it.

Can you explain the failure mechanism caused by. Tires of slightly different diameters to awd cars? One flat means 4 new tires?

The grey area is the few 4wd vehicles that have a center diff in their transfercase..... But they can lock it solid.......

You explain things nicely

Nicely explained!

In 10 years, we'll start to see off-road 4x4 M5 builds that could rival the X5 capabilities

BMW GB are right - we Brits use the terms 4WD and AWD interchangeably, assuming the vehicle has four wheels, of course. We also find it weird that Americans call just the gearbox the transmission, whereas we call anything from the clutch or torque converter to the driveshafts the transmission.

Be cool to have you do a bunch of truck reviews, offroad, trailering, etc. Nobody talks about the physics/engineering of it as in depth as I imagine you would!

This is the best explanation I have seen.

Don't really understand why BMW had to reinvent the wheel here. The E63S managed a RWD only mode with AWD. And you said it, AWD is better in the corners. Nevertheless it's nice tech.

Short answer : AWD= center diff vs 4WD= no center diff (dog clutch, clutch pack, etc)

Exigent video very well done. Thanks.

Thx for explaining that.

James May: "I like him, he know's what he's talking about"

4WD car with rear bias as the Nissan GTR if I'm not mistaken.

Awesome presentation 👍👍👍

One of, if not the best channel on KZfaq

Great video as always, but I disagree. There are too many different mechanical systems for just two terms. I do understand the colloquial differences between 4WD and AWD, but I have yet to see a consistent mechanical difference between them. The sole exception is that a system that has a low range is not called AWD, although there might be an exception to this too. I view 4WD and AWD as technically and mechanically synonymous, with people generally using 4WD for trucks and SUVs and AWD for SUVs and cars.

I noticed 2 weeks ago that the current gen CRV use AWD while the previous gens were using 4WD and yet, it's still the same system?! I guess they changed it for marketing?!

Nicely explained. Thanks. I subscribed.

hmm never knew there was a difference till this very day. Thanks man!

Not to mention you'll get better fuel mileage with 2wd (if you want)

All wheel drive is when all 4 tires spin all the time at diffent speeds 4wheel drive is when you can have 2 or 4 wheels Spin at the same same speed all the time

cool that shed some light in the subject

Thank you. this clears up a lot.

i always thought the difference is just wheter it is permanent or not. after this, the haldex system (golf) would be an 4WD system, but after this, it would be a AWD system, because it has a differential. And the system also distributes the power itself (but just when there is slip in the front as far as i know)

Oof never been this early for an EE video 😎

brilliant explanation man! nice vid!

Thank you for making this video. I've been looking for an in-depth comparison between the two for a while. Please can you make a video covering how the Audi haldex system works too?

AWD is more light duty, 4WD more HD.

Easy, all wheel drive is when all of the wheels receive power from the transmission. Four wheel drive refers to when only 4 wheels receive power. Now give me an Engineering degree!

Nice learned a lot thanks

You're drievshaft depiction is flawless.

I'm still waiting for an AWD/4x4 that can also switch to FWD and RWD

The M5 F90 is actually 4WD which is quite quirky on a sports sedan So if I want to go drifting, I can just switch to RWD which is so much better than drift mode

you're from Jersey, Pop? I always thought you were a California guy. I love the videos and your dedication. Keep up the great work.

This channel is great!... Love it!

I had a tire shop claim that having even a 2 or 3/32 difference in tire wear on an all wheel drive vehicle will destroy the transmission. To me this makes no sense since those transmissions have limited slip differential. When you corner, tires commonly experience different speeds inside vs outside thus the reason for limited slip differential. Sounded like a scheme to sell more tires to me..thoughts?

4wd has locking low range, everything else is AWD

One of the very few KZfaqrs whose every video I have clicked the like button !!!

Thanks for the explanation