AWD vs. FWD Performance...

[SuperStretch18]

Hey everyone,

Just found this on MSN and thought I would share:

http://autos.msn.com/research/vip/Spec_Glance.aspx?year=2007&make=Mazda&model=CX-7&trimid=-1

Most of this is pretty vanilla info, but the interesting thing was under the heading "Performance"; according to these results, the 2wd performs better than the 4wd 0-60 and 1/4 mile. I'm not sure about how they got these results, and the differences are minor, but they are still interesting.

Now, I know that the typical AWD makes some sacrifice on their top end, due to parasitic loss from having to spin four wheels. However, off the line, I would have expected the AWD to trump the 2wd. The added traction should have given it an advantage.

I can say that an 8 second 0-60 is probably not pushing this car to its limits, so maybe that is the reason the AWD did not pull ahead. I am interested in thoughts though. BTW, mine is 2wd, but I'm not trying to justify my decision, only to get to the bottom of the mechanics...(drive2)

 

[DE31]

i heard somewhere once before (dont remember where or if it was a reliable source) but what i've been told is that since the two wheel drive lets the wheel spin slightly keeping the revs up in high rpm and its power range.

 

[MS6S2K]

Hey everyone,

Just found this on MSN and thought I would share:

http://autos.msn.com/research/vip/Spec_Glance.aspx?year=2007&make=Mazda&model=CX-7&trimid=-1

Most of this is pretty vanilla info, but the interesting thing was under the heading "Performance"; according to these results, the 2wd performs better than the 4wd 0-60 and 1/4 mile. I'm not sure about how they got these results, and the differences are minor, but they are still interesting.

Now, I know that the typical AWD makes some sacrifice on their top end, due to parasitic loss from having to spin four wheels. However, off the line, I would have expected the AWD to trump the 2wd. The added traction should have given it an advantage.

I can say that an 8 second 0-60 is probably not pushing this car to its limits, so maybe that is the reason the AWD did not pull ahead. I am interested in thoughts though. BTW, mine is 2wd, but I'm not trying to justify my decision, only to get to the bottom of the mechanics...(drive2)

Well, remember, the AWD CX7 weighs over 200lbs more then the FWD. At the same time, when you launch a FWD, you will break the tires loose, which is actually a good thing regarding wear and tear on drivetrain. As much as we love talking about the AWD advantage, this fact remains. It's highly abusive and strainful on the car, so I believe the AWD version would be a bit faster in 0 to 60 under a very hard launch, but to be faster it flat out needs to be abused more, so does a better 0 to 60 time matter when you basically have to beat the crap out of your car to achieve it? I don't think so. In other words, I wouldn't hold any stock in that rating. Even with the 200lbs more weight, the AWD CX7 perhaps should run a slightly better 0 to 60 time under a hard launching technique, but it really doesn't mean anything, because it's flat out gonna cause wear and damage if done regularly.

Keep in mind, this is coming from an AWD owner, so I'm extremely objective here. I felt very comfortable launching my 04 STI, because the car is beefed up more, and built for it. That's a big reason why it's such a higher priced car. The AWD system in the Speed 6 and CX7, I just don't feel has the strength and durability to withstand it over a long period of time. It's just an opinion, so no one needs to argue it or come to the defense of the Speed 6 or AWD CX7.

 

[erhayes]

Not unusual at all for a FWD to accelerated faster in the 0-60 & 1/4 mile and in top speed. The 4WD gives up weight and driveline loses in addition to the inertial losses of accelerating two additional wheels.

 

[offset_98]

Lets be real here...look at stats on the CX-7, G35, Talon Tsi / Eclipse, A4...every single one, stock to stock, runs faster than its AWD counterpart. Its weight and drivetrain loss guys! To say that you think you can get your _______ AWD car to get to 60 faster than its F/Rwd counterpart is dumb - unless you have mods and thats a different story.

Here's something, not totally accurate b/c it doesn't depict manual vs. auto trans. but its something to look at...
http://www.albeedigital.com/supercoupe/articles/0-60times.html

 

[HeavyH20]

The FWD only car will always be a tad faster than the same model with AWD. As it has been said, weight and additional parasitic drag on the drivetrain will have negative effects. But, let's see who is faster in the rain or on a snow covered road.

 

[erhayes]

Both drive systems have their good points but, AWD (which the CX 7 is not) does have a safety advantage.

 

[SuperStretch18]

The FWD only car will always be a tad faster than the same model with AWD. As it has been said, weight and additional parasitic drag on the drivetrain will have negative effects. But, let's see who is faster in the rain or on a snow covered road.

...or in the twisties.
This is all very interesting; I guess that I assumed that 2 < 4 from a dead stop. I did not even consider the additional weight in the equation...

 

[hectik1]

Lets be real here...look at stats on the CX-7, G35, Talon Tsi / Eclipse, A4...every single one, stock to stock, runs faster than its AWD counterpart. Its weight and drivetrain loss guys! To say that you think you can get your _______ AWD car to get to 60 faster than its F/Rwd counterpart is dumb - unless you have mods and thats a different story.

Here's something, not totally accurate b/c it doesn't depict manual vs. auto trans. but its something to look at...
http://www.albeedigital.com/supercoupe/articles/0-60times.html

But you forgot to add if any decent power is in the equation, FWD would most likely spin = slower times.

 

[HeavyH20]

Actually, in drag racing, you want a little bit of wheelspin. It actually helps get the car launched a little more aggressively and improves times. Zero wheelspin bogs the car and too much wheelspin is obviously bad.

 

[LordWorm]

Actually, in drag racing, you want a little bit of wheelspin. It actually helps get the car launched a little more aggressively and improves times. Zero wheelspin bogs the car and too much wheelspin is obviously bad.

Yes and no...this is true of slicks - they work best with a limited amount of slip on the road, otherwise they shake like a mofos and you have to get off the power.

On street tyres, all the "give" you need in the tyres is in the sidewall....i used to spin the front wheels up big time on the launch, now i don't, and believe me, i cut much faster 60's with street tyres not screaming/slipping/spinning at all, then when they are.

 

[1Sleepy93]

You don't get much wheel spin when launching the FWD CX. Just make sure to turn TCS off or it will fall on it's face during the launch.

 

[hectik1]

Actually, in drag racing, you want a little bit of wheelspin. It actually helps get the car launched a little more aggressively and improves times. Zero wheelspin bogs the car and too much wheelspin is obviously bad.

Depends on the car....

 

[LordWorm]

Depends on the car....

Yes...more accurately depends on power, and suspension, but MOSTLY tire choice..

9 times out of 10, on street tires (including drag radials) wheel spin is going to rob you of time. The same is true of slicks, but with the kind of power you run to warrent slicks, if you are not spinning a little off the line, you'll get a lot of shake and get sent into the nearest baricade.

For MOST street tuned cars (Regardless of the car) the best technique is to launch as close to peak torque as you can (using a 2step on turbo setups to build some boost off the line if you can!), and ride the clutch out hardcore over the first 60ft...

this will murder your clutch, but the result will be that you don't bog off the line (slipping the clutch will keep your revs up) and you won't bake the wheels.

Of course, speaking generally here - some people like to do smokey launches, but from my point of view, and personal experience, its always best to minimize wheel spin on radial tires and let your clutch and sidewall do the work for you

 

[SuperStretch18]

This is all why I assumed that an AWD would launch much more effectively than a 2WD. Again, I wasn't taking weight into account and the tests I was looking at probably did not involve huge smoky burn-outs on either end, but I am still a little surprised that the added traction does not translate into a better launch...

 

[LordWorm]

This is all why I assumed that an AWD would launch much more effectively than a 2WD. Again, I wasn't taking weight into account and the tests I was looking at probably did not involve huge smoky burn-outs on either end, but I am still a little surprised that the added traction does not translate into a better launch...

Theoretically AWD should get off the line harder - in reality its just strange... i've seen some very wild AWD drag cars (personally witnessed the world GTR skyline record get smashed at willowbank race way earlier in the year)... even though the setup is designed to deliver fixed power to front and rear wheels at the same time (at something like an 80/20 rear/front split) - as opposed to only engaging front wheel assist when traction was broken, the car launched strangely...it litterly jumped in the air...no idea what this is about, but its chronic of awd cars with big power...

for mildly hard launches, its probably a really great platform, but for VERY hard high RPM launches it appears to be very deficient.

 

[raylau63]

awd vs fwd vs rwd

Here's something I found on you tube. comparison from 5th gear: http://www.youtube.com/watch?v=K9TJecSuwIY

 

[erhayes]

AWD would probably be the quickest in acceleration IF an over abundance of horse power were available. Road or street driven car are not designed to burn rubber for the full quarter mile. Mazda "AWD" is not a true AWD in that at maximum, only about 50 power can be transfered. Vehicles with true AWD like Porsche, Audi and Subaru have ALL 4 wheels driving ALL the time and can transfer up to 80 % of the power to the rear to help acceleration.

 

[Rick's CX-7]

 0 - 60 Time
(seconds) 1/4 Mile Time
(seconds) 1/4 Mile Speed
(mph) Braking 60 - 0
mph (ft.) 
Mazda CX-7 fwd -7.78 16.00 90.80 127 
Mazda CX-7 4WD -7.99 16.02 88.20 125 
Mazda CX-7 4wd -8.22 16.27 87.10 130

The 0-60 different between FWD and AWD is 0.21sec between vehicle 1 and 2. The question is, how the hell did vehicle 2 catch up to 1 when the gap should have been bigger? Something is not correct in these numbers. At a minimum, the same .21sec difference should have been maintained throughout the run.

Rick

 

[warrusty]

You don't get much wheel spin when launching the FWD CX. Just make sure to turn TCS off or it will fall on it's face during the launch.

I agree with disabling the TCS. Just remember it automatically re-engages after 18 mph.