CNET on Current AWD Systems
CNET has a very interesting piece this morning highlighting the different technologies used by auto manufactures to put power down through all four wheels. Featuring everything from MINI’s All4 system, to Mazda’s Active Torque system, to Hybrid on-demand systems found on Lexus vehicles. Somehow though, they’ve managed to flub the All4 system’s specifications, saying that 100% of the Countryman’s power can be sent to the rear wheels. MINI’s own documentation has the power split at only 50/50. Errors notwithstanding, it’s still a very interesting look at the cross section of technologies out there to keep the rubber on the road. Check out the full article over at CNET.
<p>Frankly, a technically pretty pedestrian story, or one not that well researched. Good to see an attempt at a deeper dive, and at least gives some sense not all AWD systems are close to equal.  They can generally help getting from point A to point B in adverse conditions, but performance attributes (or not) vary a lot. </p>
<p>As some examples, on Audi/VW products, it doesn’t differentiate between the longitudinal motor cars (A4, A5, A6, A8, Q’s, etc.) with true Torsen Quattro and the transverse products (TT, A3, all the Golf derivitives, etc.) with the fairly different Synchro set up. No discussion of differences between a mechanical split front to back and a simple silicone clutch type system at the other end of the spectrum. It fails to explain at all the differences between brake based traction control systems for side to side slip and true LSD’s. Â Laughably thinks the Audi R8 is a transverse mount system rather than a mid longitudinal motor (kind of apples and size 12 shoes comparison wise).</p>
<p>Also doesn’t really explain the very important difference between a full time system and a reactive system and why it matters, especially in a rear biased system. Â Porsche proudly claims the Panamera reacts w/in 1/10 second. Â Well at 60 MPH, that’s more or less a full wheel revolution, and at 30 a 1/2 revolution. Â Lots of bad things can start happening with a decent amount of power applied principally to the rear in 1/2 to 1 full revolution where presumably the electronic nanny’s like ESP are intervening and reducing power.</p>
<p>Mini is also not a 100% rear capable system. Â Much lower tech than that, as are many volume products that hardly get mentioned (e.g. Toyota and many other front transverse based set ups). Â Fundamentallly front biased, and often max at about a 50/50 split. Â Â </p>
<p>Hey,nice post.This is the technologies used by auto manufactures to put power down through all four wheels.Thanks for sharing this article with us.Its great.I like this.Keep sharing with us.</p>