My understanding of the TLX SH-AWD is that there is always some power to the rear wheels. Check this out -- I just bought a new AWD Pilot, and am glad to see it is SH-AWD
Anyway, in theory, I would think the AWD system would mitigate premature front tire wear.
SH-AWD on the 2015 Acura TLX and the 2016 MDX, i-VTM4 on the 2016+ Honda Pilot
On the latest TLX and MDX, Acura “secretly” changed the SH-AWD system design. Below is a cut-away image showing its mechanical structure, you can see it can be considered to be a variant of the Honda VTM-4.
The major functionality differences between this new SH-AWD and the “old” VTM-4 are:
1. Rear wheels will always get power;
2. Torque vectoring feature in the rear wheels (the hardware of VTM-4 can do this too, however Honda chose to not implement it)
Compared to the previous SH-AWD, this new SH-AWD has these different features:
1. Overdrive ratio raised to 2.7% (from 1.7%) – this will decrease the possibility that SH-AWD becomes ineffective, as discussed in the above “When SH-AWD Will Not Work” section;
2. Hydraulically-controlled clutch (old SH-AWD: Electromagnetic clutch)
3. Smaller and lighter
Simply speaking, clutch packs in the new SH-AWD system are responsible for 100% of the workload, with the increased 2.7% overdrive ratio, the wear and overheating issue should be more serious than before. The reason why Acura can still let such system pass at least 10% of the torque during cruising in a straight line is: progress in the material technology make it possible to manufacture clutch plates with excellent anti-wear properties, so although there are lots of friction wear and heating under normal operating conditions, the new SH-AWD component can still maintain good reliability.
For the 2016 and up Honda Pilot, although Honda is marketing its AWD system as “i-VTM4″, it is in fact identical to the latest SH-AWD.
2015 Tech 2.4 L CBP/Espresso
Last edited by mk5; 08-04-2016 at 10:28 AM.