carguy75

LOL.

Good point.

However I still want to know what makes one one better than the other, since people like to post BMW AWD system is better or Audi is better however a lot of different factors come in play when comparing one AWD car to other, even when comparing two of the same model of AWD cars against each other.

Factors like the brand of tires, did one car have the traction control on and the other off, ground clearance to get over obstacles,suspension design/travel,etc.

So it is not the AWD system at question, but how well the car is equipped,driver skill/knowledge, and chassis design that really matters when comparing AWD systems and how they function.

However, some cars are better equipped in stock form than others to handle bad weather which can be compared against each other like auto magazines do in test articles.

But that do not mean that the AWD system is not good if the car comes with crappy all-season tires like the RX350 with the H/T Bridgestone tires in my opinion compared to a BMW with Continental or Michelin performance AS tires.

vlad_a

Let's start simple. What makes Lexus GS better than Lexus ES? Tires? Driver? Suspension travel? ECU tuning?

carguy75

It all suggestive, someone may think that the Lexus ES is better than the GS.

I personally would prefer the GS over the ES, however the ES is a very nice car also and comfortable.

However, from a performance stand-point the rear-drive GS is better handling car in my opinion.

From a common daily driving stand-point the ES may actually win more votes due to its softer suspension set-up and comfortable plush seats.

Hell, if Lexus wanted to they could may make a F-type ES model with a sports suspension/stronger 3.5 V6 that would give the GS a run for its money.

So tell me why do you think that the GS is better than the ES?

tfischer

I think the "Carguy" means "subjective." No one has accused the GS or the ES, or even their advertising, of being suggestive, although I for one would welcome the change.

vlad_a

Different architecture. RWD vs FWD. This results in better weight placement, engine sitting closer to the center and more components going to the center/rear. Front suspension also benefits from double-wishbone setup instead of common McPherson found in a Camry. This improves both handling and comfort.
You can't build an FWD sports car. Laws of physics prohibit that. When you accelerate from a standstill, the front lifts and the rear squats. The more throttle you apply, the less traction you get. That's why it is so easy to spin wheels on an FWD car. Then there's torque-steer. Left and right wheels fight each other, jerking the steering wheel on acceleration. Say hello to the understeer as well. With all the weight riding in the front, the vehicle will be prone to sliding its front end during a turn, especially when giving it gas, as turning wheels are also driving wheels.
With the RX, just like ES, been built on a universal [compromised] FWD Camry platform, it suffers from all of the above. Having partial rear wheel engagement masks this tendencies, but only to a certain extend.

Personally, I am disappointed that the RX was built on the ES platform and not the GS.
However, most Toyota [Camry] drivers won't know any better, and current crossover market proves just that. Having realized this fact, BMW is on a fast track to the mainstream market. New FWD X1 (mini) anyone?

carguy75

LOL.

Thank you for clearing that up.

Hence why my login name is"Carguy", not "Grammar Guy".

carguy75

So in your opinion a better car has better handling.

Volvo makes some of the most comfortable cars around and they are FWD based so having a RWD platform alone do not make a car more comfortable, actually it could be the other way around when it comes to rear passenger room due to the RWD losing rear passenger space due to the rear differential.

The 2016 Nissan Maxima is FWD based and it out handle many RWD sedan like the GS non-F-type, as well as the Nissan Murano(FWD based as well) out perform many other crossovers.

Suspension set-up has more to do with how well a car handle than just it platform.

However, i do agree with you that as platforms go RWD have better balance than FWD without needing a super complex suspension set-up.

Yet, like I mentioned earlier someone else may like the ES more than the GS so better handling do not make for a "better" car as a fact.

Depend on the driver preference.

vlad_a

I would disagree on Maxima being able to out-handle an RWD vehicle. It might be quicker in a straight line than some, but again, laws of physics are not on its side. I think we have determined benefits of the RWD platform. There's a reason why most exotics and sport cars are RWD-only.

The X-Drive happens to be an after-thought. An after-thought to an already great RWD setup. This allowed it to keep its RWD advantages, at the same time expanding its all-weather capability. Torque is managed more aggressively to the front wheels, since having too much RWD action will result in the vehicle attempting to get sideways.

The FWD is not without its advantages. There's a reason why it completely dominates the market. Since FWD vehicles are easier to manage in slick conditions for most drivers, there's no need for AWD to be on all the time. With most weight being in the front to begin with, the rear driving wheels have just a supplementary role to fill. Hence why their engagement is part time. Not only that, in offroading situations, the center diff will overheat and revert to FWD-only.

What really makes one AWD better than the other? Last year I was helping push out cars from a snowed-in parking lot. One of them was a Ford Explorer. As soon as one wheel started spinning, the remaining 3 got no torque. Jeep Patriot did exactly the same thing, when I helped get it out from a sand dune. When the guy I was pushing cars out with asked me if I needed help, all I had to say - I drive a Subaru! His reply was, oh yeah, those don't get stuck.

When I took our RX out on a beach, I was well aware of my limitations. I was an impostor. Things could get ugly real fast, if I didn't take it easy. I was prepared, though, with a tow strap, hand winch, a shovel and a piece of board to support the jack if it came to it.

carguy75

Now I agree that the Subaru full-time Asymmetrical AWD drive system is one of the best since all wheels have the same amount of traction all the time, hence Subaru cars actual have 4X4 units as opposed to most mainstream cars/crossovers utilizing AWD systems that runs one axle until the other axle is needed.

To clear this up, I do not believe that all AWD systems are design equally with only tires,drive skill, etc the deciding factor on how useful they are when needed or compared to each other.

My point is that a lot of people post that the RX AWD is bad but do not account for the factors that limits its function at the time.

Hence an owner need to pick the right car for their needs when purchasing the car and pay attention to the short comings when deciding.

Not all BMW have limited slip differential equipped with their AWD units, but the ones that do will out perform even other BMW that does not.

So not all BMW AWD systems are equal and so forth across different makes.

The RX AWD system is good for what the RX is designed for, mostly urban cruising.

Having good set of AS tires will allow the RX to do that reasonably well, equipping a set of dedicated snow tires would yield better results.

So no one should expect an RX to behave like an Jeep or top end BMW SUV with limited-slip, and say that Lexus AWD are crap.

FYI, the reason those cars you was pushing that were stuck had trouble is because they have open-differentials, hence one wheel spin and the car can not gain traction.

Unfortunate, having AWD just mean more wheels will spin in those situation hence AWD with limited-slip deferential or electronic-locking differential are better choices for areas that get a lot of ice and snow yearly.

carguy75

LOL.

I have tried to defend Lexus AWD system against posters that says that Acura SH-AWD and BMW X-drive is better.

Well I just discovered that i was wrong and that Lexus AWD system is not in the same league as Acura nor BMW.

This two videos explain why Lexus have very limited snow/ice capabilities to those two automakers.

Crap I thought that Lexus AWD was more advanced.

These two videos tells it all.

The Lexus does handle like crap compared to an Acura in slippery conditions and it has nothing to do with tires or drive type(FWD/RWD)unfortunately.

According to the video#2 BMW uses the same type of AWD system as Acura.

ericsan13

The first video has been posted many times and is flawed. The RX in the video lacks VDIM, which prevents slip as opposed to TRAC which activates after slip is detected. The video also claims the RX does not have hill assist which is again incorrect...

I have not seen a hill test with an RX with VDIM. Probably because not many people care about the offroad capabilities of an RX.

Edit: It is not clear if VDIM leverages a brake-based limited-slip differential effect similar to the IS-F. But it does have "Dynamic Torque Control All-Wheel Drive" which does shift torque from front-to-back as needed (but not left to right).

Edit2: Looks like 4RX uses "Enhanced-VSC" which applies individual brakes and works with traction control. Since VDIM uses traction control, the RX does use individual-wheel braking which should allow it to have a brake-based limited-slip effect.

carguy75

Actually the RX in the video should have VDIM since it is 2013 model and has the 19in sport package wheels that usually only comes with the sport package I thought.

How can anyone tell if the RX in the video has VDIM or not?

However, even if the RX in the video did not have VDIM, the AWD system still do not have the torque management that move power to the individual wheels that needs power, to control sliding so I doubt that a VDIM equipped RX would have fared any better in the roller test.

To the RX defense it would have made it up the roller if the testers would have disabled the traction control(VDIM or not) so that the RX would have enough power to pull the ramp.

So the RX could possibly pull the ramp, just not as effortlessly(safely) as the MDX.

I still like my RX over the MDX, but i must admit that i thought that Lexus AWD in the RX had the torque-management as well.

Oh well, the RX is a still a nice riding SUV.

Since I live in Georgia and in the city at that, I doubt that i will ever need such an advance system used in the Acura often, if ever to be honest; but I can see how it could be embarrassing for owners that do get stuck in snow while having a Acura MDX drive pass you with no problems at all.

Note:
Never mind the question about the VDIM on the 2013 RX model, I forgot that the 2013 RX have the F-sport models that have the sport package and VDIM with distinctive front bumper,wheels, badges.

kitlz

The F-Sport has VDIM. It's not part of the sport appearance package. The RX in the video does not have F-Sport badging on the side. And Lexus does have hill start assist in contrary to what they say. I can attest to using it in snowy conditions when I had to stop on a hill for a train. Here is the hill but this was from last Friday's snow storm. And VDIM didn't kick in.

carguy75

Thanks for clearing that up.

You are right about the hill start assist,even my 2011 RX350 has it so the testers did not even know about all the features the RX has which could have made a different on the test.

The MDX may have still performed better than the RX if the testers would have used a RX model with VDIM(since they wanted the traction control systems on) and/or used the hill start feature, but the results would not have been so one sided I believed.

vlad_a

I have VDIM. It does not do anything to create a "logical" LSD. And logicals don't work nearly as well as physical, no matter what anyone says.

They do overstate how great SH-AWD is. Pay close attention, active rear differential is in the rear only. Front is the same open diff. If the only missing roller was in the front, MDX would have gotten the same result as RX. And having a very unfavorable weight in the front, Acura doesn't handle that great. So, when things get ugly, it is not as easy to get out from a skid.