I don’t pretend to understand the technology, but I can say that in the early 90’s in the US some trucks were equipped with rear-wheel-only (drum brake) ABS. It seemed to me more like a marketing scam than anything else, because the primary advantage of ABS is it stops the front brakes from locking and therefore retain steering control during panic braking. Rear-only ABS lacks this key benefit.
Nowadays, 2 wheel ABS is rare if not cured from the US market. All GM vehicles sold in the US are available with 4 wheel ABS and with the exception of most SATURNS and re-badged imports, all GM vehicles through the 2002 model year had standard 4 wheel ABS standard, despite the fact that more than the majority of these vehicles had rear wheel drums. The continuing economic downturn is forcing GM to consider making ABS optional in order to reduce the prices of their vehicles. Ironically, this move will save about $330 off the sticker price for the owner who does not want ABS but add about $550 to the owner who wants ABS because of lost economies of scale.
4 wheel ABS without 4 wheel disc seems like a compromise and it is. Of course, ABS does not generally reduce stopping distance under normal driving conditions (dry pavement) and ABS still helps with disc/drum in wet conditions.
Ahhh, those cites. Call me academically lazy, but what I remember about the jump starting issue (I’m not going to look it up) is in the late 90’s I read that GM and Ford found a disturbing correlation with late model cars coming in for warranty service that had been jump started resulting in immediate burnt to a crisp stereos and/or engine electronics. It’s a correlation; certainly there could have been intervening, moderating or modulating variables. These manufacturers recommended not jump starting cars, but admittedly not many are going to wait for and pay the additional expense of a two truck when jumper cables are available. Perhaps not the best advice I’ve ever given, in retrospect.
Push starting a standard trans car: I did it numerous times in the 70’s without any noticeable problems. Every owner’s manual for every car I’ve owned since then that broaches this topic recommends against this practice and suggests it’s warranty voidable. That was enough for me, although I cannot explain the pathology, if there is any. That’s my story and I’m sticking to it.
Most egregious example of CAFE: the ZR-1 Corvette, hottest-ever at the time, could pull red in fifth, more than 180 mph. Shift to sixth at 180 mph and speed drops immediately to about 165. Even with 400 bhp, it could not even approach the torque/horse peak because this car was geared so tall in order achieve 25 mpg highway.
Sadly, CAFE rules also extend to individual models and the US manufacturers refuse to sell cars classifed as “gas guzzlers,” so you’d be hard pressed to find a car for sale in the US rated at less than low-twenties mpg on the highway.
