New VW engine - nice match for Yeti in future...?

[weasley]

I am about to start the process of selecting a replacement for my other car (Merc B Class). I no longer need an 'MPV' and am looking for a car to economically (but with some style and poke) do an 80 mile round trip commute. Among the shortlist are the Fabia VRs, Audi A1 1.4 TSi and the VW Polo. I was originally looking at the Polo GTi, as there is a huge gap in the engine range from the 1.2 TSi to the GTi, but they are about to launch a new engine and I got to thinking how it might work well in the Yeti.

It's a 1.4 TSi, putting out 140 bhp/250 Nm but it uses "Active Cylinder Technology" to shut down cylinders 2 and 3 under light-mid loads and speeds. This means that at motorway cruising speed it can manage perfectly well on 2 cylinders, saving fuel and lowering emissions. When asked to get going, the cylinders come back in one and a half turns of the camshaft and you get the full beans. It'll do 0-62 in 7.9s and still get 63 mpg and 107 g/km CO2.

This sounds like an ideal Yeti engine - strong when needed and frugal when not. It mates to the 7 speed DSG too.

I like the concept of the engine too, as the fuel saving happens most of the time, unlike stop/start and brake regen (which it also has by the way) which only work in transient and urban traffic (so useless on the motorway).

I'm planning a test drive as soon as I can get one (the car is launched in the UK next month).

[BossFox]

Sounds impressive. Would be great with the DSG 7 speed box.

[Babs]

Autocar have done a review on the Polo GT BlueMotion (which this engine comes in), would make an ideal engine for a large chunk of cars, to be honest!

[Phil-E]

Sounds impressive. Would be great with the DSG 7 speed box.

Yeh. No current cars with the DSG have start/stop do they though? Can't be hard to do though. Surely just a programming issue for when handbrake on and neutral selected.

Phil

[Babs]

Could even do it when handbrake is on for more than 5 seconds or something. Box can disengage by itself, surely?

[BossFox]

Yeh. No current cars with the DSG have start/stop do they though? Can't be hard to do though. Surely just a programming issue for when handbrake on and neutral selected.

Phil

Not sure on DSG, but some cars do have an automatic box and stop start now.

I think mercs have it and I know the 8 speed auto box from Jaguar/Land Rover has the ability to do so now also, but these are recent improvements.

[Expatman]

Yeh. No current cars with the DSG have start/stop do they though? Can't be hard to do though. Surely just a programming issue for when handbrake on and neutral selected.

Phil

I believe that some Audi models have stop-start with the DSG box - will do some research to identify models.

[Phil-E]

Ah right.

Like I say I see no reason why not and it is surely just down to how they program the car.

Think it would probably make most sense to stop the engine if left in gear, handbrake on and foot off the brake. The as you press the brake again the engine starts back up handbrake off and you're away.

Phil

[Zib]

Yeh. No current cars with the DSG have start/stop do they though? Can't be hard to do though. Surely just a programming issue for when handbrake on and neutral selected.

Phil

The Audi A1 1.4 TSI DSG does. I wasn't too impressed with the combination when I drove it a few weeks ago, because it operates in Drive, and only restarts when you touch the accelerator, so I found myself actively trying to keep the engine going. Oddly enough, the engine keeps running when the handbrake is on and Neutral selected... Personally, stop/start would work better for me if it only operated when the handbrake was put on, so I could actively tell the car that I was happy for the engine to cut.

Edit: On reflection, I think the engine restarts when the brake pedal is released. It still felt not very well resolved compared to stop-start on the manual gearbox.

Edited 30 August, 2012 by Zib

[Phil-E]

The Audi A1 1.4 TSI DSG does. I wasn't too impressed with the combination when I drove it a few weeks ago, because it operates in Drive, and only restarts when you touch the accelerator, so I found myself actively trying to keep the engine going. Oddly enough, the engine keeps running when the handbrake is on and Neutral selected... Personally, stop/start would work better for me if it only operated when the handbrake was put on, so I could actively tell the car that I was happy for the engine to cut.

Oh dear. That sounds really counterintuitive. Must be a weird feeling having to press the accelerator before the engine kicks back in.

If they get it right with this new engine then it sounds like a cracking package.

[rockhopper]

I thought I read a review of the Audi Q3 with a 2.0 TDI (CR200?) DSG with stop start

[nickguzzi]

Is it similar the General Motors Gen 111/1V type "displacement on demand" / "active fuel management"? These were very seamless iterations of reducing consumption by "switching off" cylinders, which was done by collapsing the hydraulic cam followers on the particular cylinders concerned.

Switching off your engine is a Swiss law I think, not sure if it is Federal or just some Kantons. Maybe other countries have it as law? lots of folk do it in Germany as a matter of course.

[weasley]

It is a similar concept to the mentioned cylinder deactivation but they are usually applied to a V engine where a whole bank can be shut down; this is 2 out of 4 on the same camshaft. The mechanism is quite neat; the cam lobes for the inner two cylinders are mounted on splines and can be slid along the camshaft by positive-action actuators so that the cam lobe effectively just becomes a base circle, so no cam lift on either inlet or exhaust valves.

[AlleyCat`]

Slightly off topic but my stop/start will cut in even if the handbrake is not engaged (not a DSG Model).

Is that correct behaviour or not?

It works solely off selecting neutral and the car been "almost" stationary.

Edited 31 August, 2012 by AlleyCat`

[Big Rich]

That's the correct behaviour. As long as gearbox is in netrual the engine will start stop if the parameters are correct