Would you still buy a Subaru if you didn't need AWD?

[SBT]

And four friction pads are more effective than two...all else equal

[Rick]

AWD is seriously over-rated. However, a Subaru forum is probably not the best place to debate this as everyone has a dog in the race.

 

Seriously though, it is the meat behind the wheel and the meat on the wheels that really matters.

 

I couldn't disagree more. I've owned both RWD cars with snow tires (GTO), and FWD cars with snow tires (Accord) and neither one performed as well in the snow as my Legacy with shitty all season tires. For a daily driver I will always drive an AWD car.

[StoplightAssassin]

And clearly you are the expert...

 

I never said I was an expert. You clearly have a much better understanding of vehicle dynamics based upon researching internet articles.

 

I choose not to rely on wrong assumptions gathered off of clear and accurate data.

[SubaruFanatic]

I couldn't disagree more. I've owned both RWD cars with snow tires (GTO), and FWD cars with snow tires (Accord) and neither one performed as well in the snow as my Legacy with shitty all season tires. For a daily driver I will always drive an AWD car.

 

Thank you at least this guy gets it

[SubaruFanatic]

Prove it. Explain how this is so? The tires still have to slow the vehicle, it doesn't matter what makes them slow down.

 

seriously you must have never either driven a manual or you just drive like an old man and never downshift to slow you down. When you downshift the engine acts as the brakes, why do you think tractor trailers rely on engine braking so much.

 

and if you have 4 wheels slowing you down rather than 2 then duh its going to be more effective. if you downshift and dont rev match correctly with rwd your going to lock up the rear wheels.

[ShrinerMonkey]

seriously you must have never either driven a manual or you just drive like an old man and never downshift to slow you down. When you downshift the engine acts as the brakes, why do you think tractor trailers rely on engine braking so much.

 

and if you have 4 wheels slowing you down rather than 2 then duh its going to be more effective. if you downshift and dont rev match correctly with rwd your going to lock up the rear wheels.

You do know that ALL cars have 4 wheel stopping right? It doesn't matter what causes the wheels to slow down. In fact by using the engine to brake you loose the benefits of ABS and its ability to prevent wheel lock up. The FRICTION with the ROAD is what causes a car to stop. I'm not sure what you guys don't get here.

 

Tractors rely on engine braking to prevent brake over-heating. It has nothing to do with the efficacy of engine braking over friction brakes.

[ShrinerMonkey]

And four friction pads are more effective than two...all else equal

Right, ALL cars have 4 friction pads, even FWD and RWD because ALL cars have 4 wheel braking.

[Rick]

Yeah seriously. Friction with the road is what makes a car stop, not the brakes or the engine, those just slow the wheels.

 

Are you for real? You seriously don't think that the cars brakes are what stops the car? Then why don't you remove your brakes and let friction from the road stop your car for you. Let us know how that works out.

[thefultonhow]

Are you for real? You seriously don't think that the cars brakes are what stops the car? Then why don't you remove your brakes and let friction from the road stop your car for you. Let us know how that works out.

 

Okay, let's say you have one car with shitty no-name 175/70-14 (this used to be a Subaru tire size!) touring all-season tires and 1-piston brakes, and OEM pads. Then you have the same shitty tire in the same small size with 4-piston brakes and Hawk HPS pads. Which one will stop in a shorter distance on dry pavement? Hint: it's a trick question!

 

Now, let's say you have the same 4-piston brakes with Hawk HPS pads, but put on max performance summer tires in the 175/70-14 size. Then, take off those crappy wheels and mount the same model of max performance summer tires on 18x8" wheels. Does the braking performance change? Surely not, right? You're using the same brakes...

[SBT]

Right, ALL cars have 4 friction pads, even FWD and RWD because ALL cars have 4 wheel braking.

 

And you still refuse to see the point - I'm not talking about using "brakes" whether they're ABS-enhanced or simply calipers on rotors or shoes in drums. - NO BRAKES!

 

I'm talking about a true-AWD vehicle's inherent capability to, as I mentioned earlier, stop faster, manuever quicker and accelerate with more alacrity, due to the very reason that you mentioned.. four contact/friction points (tires) connected to the drivetrain.

 

Take the brakes out of the equation - use the mechanical advantage (and parisitic drain on momentum) to slow each of the four wheels (something you cannot do on a 2WD - FWD or RWD and you have to rely on "brakes" to make up the difference) and then reapply force to each of the four wheels - each in concert with the other to regain momentum. The symmetrical AWD vehicle, similarly-equipped, will out-perform a FWD/RWD every time, slowing/stopping (without brakes), starting and turning under less than ideal road conditions.

 

Again - all else equal where the contact/friction points are concerned.

[thefultonhow]

And you still refuse to see the point - I'm not talking about using "brakes" whether they're ABS-enhanced or simply calipers on rotors or shoes in drums. - NO BRAKES!

 

I'm talking about a true-AWD vehicle's inherent capability to, as I mentioned earlier, stop faster, manuever quicker and accelerate with more alacrity, due to the very reason that you mentioned.. four contact/friction points (tires) connected to the drivetrain.

 

Take the brakes out of the equation - use the mechanical advantage (and parisitic drain on momentum) to slow each of the four wheels (something you cannot do on a 2WD - FWD or RWD and you have to rely on "brakes" to make up the difference) and then reapply force to each of the four wheels - each in concert with the other to regain momentum. The symmetrical AWD vehicle, similarly-equipped, will out-perform a FWD/RWD every time, slowing/stopping (without brakes), starting and turning under less than ideal road conditions.

 

Again - all else equal where the contact/friction points are concerned.

 

It's a moot point in low-friction situations. The tires will break loose before you reach the limits of your brakes. So who cares if you have extra braking power in the form of engine braking?

 

Don't get me wrong, I agree that where engine POWER is concerned, AWD has a considerable advantage in low-traction conditions (although, so do snow tires). But when applying power is taken out of the equation, AWD loses all advantages.

[biturbowagon]

Are you for real? You seriously don't think that the cars brakes are what stops the car? Then why don't you remove your brakes and let friction from the road stop your car for you. Let us know how that works out.

 

I think you (and others) missed the point.

 

It does not matter how good your brakes are, nor whether one is using brakes or engine braking; if your tires aren't any good or are a mismatch to the conditions, you're not going to stop very well, or possibly even be able to stay on the road.

[Rick]

Okay, let's say you have one car with shitty no-name 175/70-14 (this used to be a Subaru tire size!) touring all-season tires and 1-piston brakes, and OEM pads. Then you have the same shitty tire in the same small size with 4-piston brakes and Hawk HPS pads. Which one will stop in a shorter distance on dry pavement? Hint: it's a trick question!

 

Now, let's say you have the same 4-piston brakes with Hawk HPS pads, but put on max performance summer tires in the 175/70-14 size. Then, take off those crappy wheels and mount the same model of max performance summer tires on 18x8" wheels. Does the braking performance change? Surely not, right? You're using the same brakes...

 

 

I never said that tires were not a part of the equation. The person I quoted stated that brakes had nothing to do with stopping the car.

[thefultonhow]

I never said that tires were not a part of the equation. The person I quoted stated that brakes had nothing to do with stopping the car.

 

Actually, he didn't... Go back and read his post. He said that brakes slow the wheels, but the wheels/tires are what ultimately cause the car to stop.

[Rick]

Actually, he didn't... Go back and read his post. He said that brakes slow the wheels, but the wheels/tires are what ultimately cause the car to stop.

 

Well he's wrong. It's a combination of both. You could have the stickiest tires in the world but if your brakes suck then your car will stop poorly.

[SBT]

It's a moot point in low-friction situations. The tires will break loose before you reach the limits of your brakes. So who cares if you have extra braking power in the form of engine braking?

 

Don't get me wrong, I agree that where engine POWER is concerned, AWD has a considerable advantage in low-traction conditions (although, so do snow tires). But when applying power is taken out of the equation, AWD loses all advantages.

 

In zero-to-almost-no friction situations, neither brake nor drivetrain braking is going do you much good. But, given a choice between brake braking and drivetrain braking on a somewhat tractive surface, I prefer drivetrain braking as a I can modulate throttle to reduce slip during slowing/stopping situations - brakes can (and do) cause wheel lock-up, even with ABS - hence my driving preference (and recommendation) for drivetrain braking. Bottom line, AWD provides advantage going and stopping.

 

Maybe it's more experiential, but the thread topic of owning a Subaru even if AWD is not needed, does bring out the passion for these cars and their symmetrical AWD systems. I realize that some own and use their Subarus as daily drivers A2B-only, some push them to the limit, while others fall in between these two points. I own five (was actually up to six at one point) and I rally them, track them, race them, actively look for less-than-ideal road conditions to run them, and have put them through their paces (some more actively than others) over the years. They are over-engineered to provide reliability, safety, balance at the limits, and to go-and do, what/where others dare-not. It's what makes a Subaru, well, a Subaru.

[rock2534]

I think the discussion is getting out of the realm of most drivers situations, talking about zero friction surfaces and whatnot. Lets face it, if your area is that sort of condition, you really shouldn't have gone out driving in the first place.

 

I love having the ability to engine break, in combination with using the breaks in the snow. It relieves the tires of having to provide all of the stopping force by slowing the entire wheel. Doing too much of either will not produce good results, but done together, and in moderation makes driving in snow quite easy. Especially with snow tires.

 

Rick, I say to each his own, but I just can't see how you felt your awd with AS's was better than your Accord with snows. I basically came from the same situation, Acura with blizzaks to the LGT with the oem's. The Acura was better than the LGT by a mile...traction is traction. Now the LGT with the nokians, is night and day better than the Acura with snows.

[ShrinerMonkey]

Well he's wrong. It's a combination of both. You could have the stickiest tires in the world but if your brakes suck then your car will stop poorly.

To a degree, but we are talking apples to apples cars, the only difference is one has AWD. The car with the most friction between the tires and road surface will stop faster, it doesn't matter what you are using the engine or brakes to slow the wheels as both would be all wheel braking.

 

Listen, there are numerous tests out there if you want to read that show that AWD w/ AS tires is outperformed by 2WD with winter tires in winter conditions but if you want to keep drinking the Kool-aid so be it. AWD with snows, yeah, great combo. Just don't expect AWD to be some miracle that turns cars into superior handling and performing winter machines without the proper driver and tires for the conditions.

[BAC5.2]

The center diff works under braking as well. The fronts help brake the rears, and the whole car will be inherently more stable under braking.

 

AWD cars don't engine brake any better than 2wd cars.

 

Since I am probably one of the only people here who has owned a front wheel drive, a rear wheel drive, and an all wheel drive Subaru, I am the ranking authority.

 

You guys are ridiculous for arguing about this for 2 pages.

 

I think I've sold myself on getting a C63 AMG. They are like an upscale hoon-mobile. Kind of the Dukes of Hazard meets The Clampetts.

[ShrinerMonkey]

Here is some information from Stoptech:

While almost every current passenger car is capable of a single stop from maximum speed at or near the limit of tire adhesion, the braking systems of most passenger vehicles and light trucks and some sports cars are not adequate for hard or sport driving or for towing. Most stock brake systems lack sufficient thermal capacity - the system's ability to absorb and transfer heat by conduction, convection and radiation into the air or surrounding structure during severe driving. In addition many stock calipers and their mountings are structurally not stiff enough at higher line pressures and the resultant higher clamping loads. That is why even though there is enough front brake torque to lock the front wheels at highway legal speeds, caliper flex at the increased system pressure required to stop the car from high speed may prevent wheel lock up. Needless to say, most OEM brake pads are also not designed for severe use, since cold stopping performance and quiet operation typically are considered more important to new car buyers.

 

Several factors should be considered in the selection of high performance aftermarket braking systems. Some have to do with performance and safety, some with ease of installation and some with cost. The object is to select the system that will reliably fulfill your long-term needs with the least trouble and the least cost.

There are a few basic facts that must always be kept in mind when discussing brake systems:

 

1) The brakes don't stop the vehicle - the tires do. The brakes slow the rotation of the wheels and tires. This means that braking distance measured on a single stop from a highway legal speed or higher is almost totally dependent upon the stopping ability of the tires in use - which, in the case of aftermarket advertising, may or may not be the ones originally fitted to the car by the OE manufacturer.

 

2) The brakes function by converting the kinetic energy of the car into thermal energy during deceleration - producing heat, lots of heat - which must then be transferred into the surroundings and into the air stream.

 

The amount of heat produced in context with a brake system needs to be considered with reference to time meaning rate of work done or power. Looking at only one side of a front brake assembly, the rate of work done by stopping a 3500-pound car traveling at 100 Mph in eight seconds is 30,600 calories/sec or 437,100 BTU/hr or is equivalent to 128 kW or 172 Hp. The disc dissipates approximately 80% of this energy. The ratio of heat transfer among the three mechanisms is dependent on the operating temperature of the system. The primary difference being the increasing contribution of radiation as the temperature of the disc rises. The contribution of the conductive mechanism is also dependent on the mass of the disc and the attachment designs, with disc used for racecars being typically lower in mass and fixed by mechanism that are restrictive to conduction. At 1000oF the ratios on a racing 2-piece annular disc design are 10% conductive, 45% convective, 45% radiation. Similarly on a high performance street one-piece design, the ratios are 25% conductive, 25% convective, 50% radiation.

 

3) Repeated hard stops require both effective heat transfer and adequate thermal storage capacity within the disc. The more disc surface area per unit mass and the greater and more efficient the mass flow of air over and through the disc, the faster the heat will be dissipated and the more efficient the entire system will be. At the same time, the brake discs must have enough thermal storage capacity to prevent distortion and/or cracking from thermal stress until the heat can be dissipated. This is not particularly important in a single stop but it is crucial in the case of repeated stops from high speed - whether racing, touring or towing.

 

4) Control and balance are at least as important as ultimate stopping power. The objective of the braking system is to utilize the tractive capacity of all of the tires to the maximum practical extent without locking a tire. In order to achieve this, the braking force between the front and rear tires must be nearly optimally proportioned even with ABS equipped vehicles. At the same time, the required pedal pressure, pedal travel and pedal firmness must allow efficient modulation by the driver.

 

5) Braking performance is about more than just brakes. In order for even the best braking systems to function effectively, tires, suspension and driving techniques must be optimized.

 

For maximum brake potential, vehicles benefit from proper corner weight balance, a lower CG, a longer wheelbase, more rear weight bias and increased aerodynamic down force at the rear.

[SBT]

AWD cars don't engine brake any better than 2wd cars.

- yeah, we can agree to disagree on that one. But four wheels slowing a vehicle via engaged AWD drivetrain braking does bring more parasitic momentum loss to bear than a 2WD.

 

 

Since I am probably one of the only people here who has owned a front wheel drive, a rear wheel drive, and an all wheel drive Subaru, I am the ranking authority.

 

Interested in what the RWD Subaru was?? Broken RX?

 

I think I've sold myself on getting a C63 AMG. They are like an upscale hoon-mobile. Kind of the Dukes of Hazard meets The Clampetts.

 

Nice - should be a lot of fun. Can you say unintentional (more likely intentional) drift-mobile.

[thefultonhow]

Interested in what the RWD Subaru was?? Broken RX?

 

Welded center diff on a first-gen Legacy Turbo.

[BAC5.2]

- yeah, we can agree to disagree on that one. But four wheels slowing a vehicle via engaged AWD drivetrain braking does bring more parasitic momentum loss to bear than a 2WD.

 

Parasitic drivetrain loss during engine braking will have as much effect on "braking" distances as a few flies hitting the windscreen.

 

I've actually had a rwd subaru, I've compared it to the exact same car in awd mode. The difference is infinitesmal and not enough to base a solid argument on.

 

Interested in what the RWD Subaru was?? Broken RX?

 

A 400hp first gen legacy.

[Rick]

To a degree, but we are talking apples to apples cars, the only difference is one has AWD. The car with the most friction between the tires and road surface will stop faster, it doesn't matter what you are using the engine or brakes to slow the wheels as both would be all wheel braking.

 

Listen, there are numerous tests out there if you want to read that show that AWD w/ AS tires is outperformed by 2WD with winter tires in winter conditions but if you want to keep drinking the Kool-aid so be it. AWD with snows, yeah, great combo. Just don't expect AWD to be some miracle that turns cars into superior handling and performing winter machines without the proper driver and tires for the conditions.

 

 

Kool-Aid??? For your information I currently have a set of Hankook Icebears mounted to the stock 17's. I only had the stock Potenza's for the first winter I had the car. My last ten daily drivers have had a designated set of snow tires. So get off of your high horse!

[thefultonhow]

Kool-Aid??? For your information I currently have a set of Hankook Icebears mounted to the stock 17's. My last ten daily drivers have had a designated set of snow tires. So get off of your high horse!

 

He's talking about the "AWD is the be-all and end-all of foul-weather performance" Kool-Aid, not the "All-seasons are amazing" Kool-Aid. Although both types of Kool-Aid are ultimately incorrect.

 

Funny story -- I managed to get my old Legacy stuck when it was on bald all-seasons. Because it was AWD, it required someone pushing on the right side so that I wouldn't slide downhill into some parked cars. If it were FWD, I would have been okay with just the two people pushing on the back.