Automatic Car Help Needed Please

knightstyle

The Smart Fourfour is just a pimped up Mitsubishi Colt, or so I was told, both are a good choice though.
Does an automatic license allow you to drive a CVT?
Our Toyota Auris MMT gives over 50 mpg mostly town driving, and now we are used to it it is fine.

tyrone2014

wow thank you very much for all the reply its been very helpful and good read thank you for taking the time to help out another person because im trying to save on fuel i think the honda jazz might be the one for me its the only cvt sytem that people dont say bad things about anyone here driven one /?

Lum

knightstyle wrote: »

Does an automatic license allow you to drive a CVT?

Yes it allows you to drive a car that changes gears for you.

It even allows you to drive cars with tiptronic boxes or other ways of manually specifying what gear you want.

I don't know if there is a legal definition, but the common sense definition would be the presence of absence of a manually operated clutch as this is the big skill that you need to get right to get a manual licence.

Joe_Horner

Lum wrote: »

Ok, I got some details wrong, but my point still stands. I just remember my dad having one when I was a kid. I think it was a C reg so made some time around 1986.

Personally I really like the idea of a CVT. What I don't like is these computer controlled CVTs that are programmed to change in stages to simulate a traditional auto.

I like the idea that you can have the exact optimum gear ratio for either acceleration or for fuel efficiency, and computer controlling that should be awesome.

On a C plate it would have been either "early C" (1965 ish) or Volvo badged. Volvo bought Daf cars out in around 1976 but continued using the transmission in their version of the Daf 66 and in the 340 series.

As for CVT with artificial changes to keep the driver happy - that's just plain wrong! The whole point of a CVT is that when you hit the throttle the engine goes straight to its maximum torque revs and sits there till you're finished accelerating. Given appropriate gearing, max torque revs will provide the fastet and most fuel efficient acceleration possible and a CVT provides exactly the ratio to do that in.

One that did make me snigger was one of the recent boxes that had full auto and "sports" mode selectable. Full auto was stepless CVT, sports mode put nice revvy gear changes in. The revvy bit made it appear more "sporty" (and use more fuel as you'd expect from a sport mode) but actually made acceleration worse than leaving it in auto!

Must've been a pure marketing department input on that one

Joe_Horner

Lum wrote: »

... the common sense definition would be the presence of absence of a manually operated clutch as this is the big skill that you need to get right to get a manual licence.

That's pretty much exactly the definition that the DSA gave when we asked what sort of test my partner should book in our Colt AMT a few years back.

worried_jim

I had a Honda Civic 16esi auto and it was a lovely nippy drive. You will easily get one in your budget.

rev_henry

Joe_Horner wrote: »

Like this one in my daily driver

http://www.youtube.com/watch?v=n03FAEAZN80

They actually brought them out in 1959 (mine's a '66) and the bad reputation even then was generally undeserved. People just didnt like the way they drive or the idea of being driven by rubber bands - although no-one thinks twice about having the most highly loaded component in their engine driven by one nowadays, even though a broken Daf belt means carry on driving on one while a broken cam belt generally means a new engine!

The Dafs do give a good idea of the efficiency of CVT though - 30 BHP, 746cc aircooled engine that will sit at 70mph all day (provided you don't hit a hill) and keep up with urban traffic effortlessly, while returning 50mpg on a run without relying on computers or fuel injection

Ok that looks really cool but I can't get my head around how it works at this time of night!

OP surprised insurance on an Accent is a lot. I had one as my first car when I was 18 and used to get 43mpg with reasonable insurance. Ok it was a manual but I seem to remember there being lots of autos around.

Lum

rev_henry wrote: »

Ok that looks really cool but I can't get my head around how it works at this time of night!

Very simplified, instead of a pulley you have two cones with the narrow ends facing each other. The rubber band wraps around the gap in the middle of the cones and around a similar set at the other end.

By moving the cones closer together, the rubber band is forced outwards, effectively making it a larger pulley. By moving the other set of cones further apart, the rubber band moves inwards, making it a smaller pulley and meaning that the band doesn't need to change length.

With this you can have either a large input pulley and a small output pulley, or a small input pulley and a large output pulley or any position in between, giving you an infinitely variable ratio.

The old Daf system set the ratios using some mechanical system that I wont even attempt to understand. Modern ones will be computer controlled, and may use systems other than variable pulleys, such as the Nissan Extroid CVT, though I wouldn't recommend that Nissan design as it seems to be a maintenance nightmare. They only used it on one Japan-only car so you shouldn't worry about encountering it in the wild.

Joe_Horner

Great description, Lum

The Daf system was essentially very simple. The rear (driven) pulleys - the thinner ones at the top in the vid - are heavily spring-loaded together and the front (drive) pulleys have those big drums on the outside which have centrifugal weights attached to levers inside.

As the car speeds up, the pulleys spin faster, the weights move out, and the levers push the two halves of the pulley together. That pulls the belt "out" on the front pulleys, which forces them down into the rear pulleys against their springs. That gives a bigger "gear" at the front and a smaller one at the back. The two belts "change" independently of each other, which gives a differential effect in corners but always maintains drive to both wheels (so limited slip effect).

As the car slows down, the weights move back in which allows the front pulley halves to separate and the springs in the rear pulleys can force them closed again.

There's a minor complication involving vacuum fed from the manifold but that's just for refinement - the system still works with the vacuum system disconnected but is a little slower in responding to changes in load.

tyrone2014

now i decided for a first car better just get some cheaper and later on get a better car so i think i will go with
Honda Civic if its 1.4 then is cheap to insure or as
rev_henry said a Hyundai Accent 1.5 rechecked the insurance and its cheap aswell which one do u think will be better for fuel ?