OT: Suitable small auto car for elderly mother

[Dave Plowman (News)]

Depends what you mean by successful. Most seem to have a short life which results in the car being scrapped due to replacement costs.

[Tony Bryer]

Like all CVT systems the DAF Variomatic had split pulleys which moved in and out to change the effective diameters and thus the 'gear' ratio. Being designed in a pre-electronic era, the drive pulley diameter was adjusted according to two inputs: inlet manifold vacuum (which (IIRC falls when the engine is under load) pulled the ratio down and centrifugal force on weights increased the ratio

said before, the secret to good progress was to feed in the power gradually and let the revs and speed build together.

[Dave Plowman (News)]

That's only because the engine was even cruder than the transmission. ;-)

[Skipweasel]

Fun while they last, though.

[Tony Bryer]

Possibly true of the earlier 33 and 44 twins, but the 55 and 66 used Renault 1108/1289cc engines - not sophisticated but no more crude than what else was around at the time.

[Tim Streater]

You're right: see below shamelessly copied from Wikipedia:

The 45 was available with Continuously Variable Transmission (CVT) supplied by the German manufacturer ZF Sachs AG which had previously been used in the MGF. This particular design of CVT consists of an oil-cooled laminated steel belt (with external oil cooler) running on variable pulleys. MG Rover had many CVT failures returned to the supplier. Rover's own manual gearbox factory had been retained by BMW during the sale which created MG Rover. After buying its own gearbox designs from BMW for a time MG Rover eventually sourced an alternative supplier and later Rover 25/45 models up to 1.6 litre were fitted with Ford gearboxes.

[Dave Plowman (News)]

I'm still not sure what that means. To the best of my knowledge BMW don't make *any* gearboxes - and anyway non would be suitable for a front drive car as BMW didn't make one until the new Mini.

[The Natural Philosopher]

I think, as with injection kit, there are at most 6 or so gearbox manufacturers in the WORLD , for domestic cars, and a similar number of racing gearbox suppliers.

Getrag comes to mind..

[Andy Dingley]

It was vacuum operated, from the manifold. Which is why opening the throttle wide tended to confuse it.

If you put it into a trike with home-made Kegresse tracks and stick manual control handles on each side, you can build yourself a happy- shopper Kettenkrad...

[Dave Plowman (News)]

My 'conventional' auto has vacuum sensing and like all those for maximum performance you simply floor the throttle. This also operates the 'kick down' which holds it in the low gears up to the maximum speed the car is capable of in them.

Nor is this new. '50s Borg Warner boxes like the DG would start in second gear unless you floored the throttle when they'd then start in first.

If the DAF engine wouldn't produce maximum torque with the throttle wide open it was as I said a crude device. Or rather the carb was.

[The Natural Philosopher]

Any auto box is always second guessing at some level, what you are trying to do.

They have got better at it over time.

You either learn to fool them , live with them, or buy a manual :-)

[Tim Streater]

My C4 has a level sensor so that, when stopped in traffic on an uphill slope, if you take your foot off the brake, it holds it for max(3 secs or until you press gas pedal). I'm wondering if it uses the same trick to know to change down when going down hill and my foot's off the pedal.

[Skipweasel]

My Xantia does something similar - but not on purpose. The brakes take about half a second to fully release - they're not on hard enough to impede progress, but on a reasonable slope it doesn't roll back in a hurry. I could fix it - but it ain't bothering me or the MOT.

[Steve Firth]

Heck, that's almost as good as a petrol powered yank tank. But not quite.

Umm not sure what that says about diseasel longevity.

"Almost as good as the competition"?

[Adrian]

[e-mail] (Steve Firth) gurgled happily, sounding much like they were saying:

I think the Saab's on about 230k at the mo.

Hell, even the (1.1 4spd) 205's closing on 140k.

I used to know somebody with a CX c-matic on about 400k miles, with full history. Neither engine or box had ever been out, and the head had never been off.

You could have shoved your head through some of the holes in the shell, but the mechanicals were _spot_ on...

[Dave Plowman (News)]

Not in terms of a full bore take off from rest. You simply floor it and leave it alone. 'Twas thus from the very first ones made.

[The Natural Philosopher]

No,. you put your left foot on the brake, then just enough revs till the auto clutch start to engage Then floor it and take your foot off the brake. After having engaged sport mode first.

[Huge]

I occasionally have work done by Offord Motors

loaners are SAABs with astronomical mileages; I've never had one with less than ~300K and a couple of times over 500K. The interiors are, how shall I say, well patinated, but they seem to work OK.

[Dave Plowman (News)]

The various clutches in an auto engage instantly you select drive or whatever. The start from rest is achieved by the torque convertor. What you're describing is 'stalling' the TC and is indeed the way to get the very fastest takeoff. But don't do it for long as you'll overheat the transmission.

But on any auto I've ever come across, sport mode makes no difference to the 'kickdown' setting. It would be a nonsense if it did. Flooring the throttle means you are calling for its best efforts.

[The Natural Philosopher]

Dunno,. My jag would only redline before changing up in sport mode.