[Maturedriver]

Is it my imagination but does the GTE accelerate faster when changing gears using the paddle shift levers whilst in EV mode. Not so much from a standing start but I think it does once on the move. Say over 30 mph. Logic tells me that since electric motors develop maximum torque from 1 rpm gears should not make any difference.

 

[TomH]

Gears make a difference to the torque experienced at the wheel. And that's what propels the car forwards. For a given motor torque, a low gear will produce a higher torque at the wheel.

Whether you improve things by playing with the paddles, depends on whether you are better at optimising the transmission than the automatic programme in the DSG gearbox. However you will definitely feel as if you are contributing to the process. So it may seem faster. Cue for comparative tests if you can be bothered!

 

[tom66]

The gears in the GTE are there really there because the car has an engine which requires a gearbox so may as well take advantage of that - it gives a marginal benefit in efficiency and allows for a smaller motor.

In e-mode the gears pretty much 'count up' as your speed gets faster, and the motor shifts at a lower point to when the engine would shift, it seems around 1000 rpm. This means the car is usually in 6th gear by 30 mph, when it might only be in 4th or 5th gear in hybrid mode.

The car is clever though and it always keeps the gearbox and engine within range of kickdown - so if for any reason the engine has to take over (low battery for instance) it won't have selected a gear that does not allow the engine to immediately clutch in.

 

[Maturedriver]

Showing my ignorance of things electrical, does 30 mph in 6th gear use less power (and therefore better range) than 30 mph in 4th or 5th?

 

[tom66]

Running any machine at a lower rpm will generally improve its efficiency as there are less frictional losses. But you can't do that with combustion engines as the combustion becomes unstable at lower rpms and the torque the engine can produce reduces - this produces a very 'rough' ride (or even stalls the engine altogether).

That said given how efficient electric motors are you'd be talking about e.g. 95% efficiency vs 92%, it's better than nothing but it's not as dramatic as some might expect. So in general electric vehicles use a single speed gearbox as the cost/weight of the gearbox outweighs any benefits. A GTE has an ICE, and an ICE needs a multi-speed or variable ratio gearbox, so you may as well use it if it is there.

 

[Maturedriver]

Thanks for that Tom. I guess brushless electric motors have very little friction regardless of motor speed. Interestingly the only other car, I can think of, with a electric motor with a gearbox is the all electric Porsche Taycan. A two speed 🤔.

 

[cdlb]

I had a very brief play with the paddle shifters in EV mode on my Passat and didn't notice any difference in how the car felt. I was doing my usual country road driving (40-60mph speed range) but I wasn't "having fun" while trying it, so there might be a difference if you're a bit more spirited.

 

[GTEowner]

The strategy of the transmission seems to be to assume the engine might needed to join the party at any moment so we need to be in an appropriate gear for that, it often annoys me around town so I put it in manual and then knock it into second at the first opportunity pulling away (first gear is a bit rough) - the rest of the time I don't touch the gearbox, just let it go up the gears when it has to, and back down when it absolutely has to.

 

[tom66]

Thanks for that Tom. I guess brushless electric motors have very little friction regardless of motor speed. Interestingly the only other car, I can think of, with a electric motor with a gearbox is the all electric Porsche Taycan. A two speed 🤔.

Yup, the two-speed there allows the Taycan to achieve higher efficiency and high speed. It allows the RWD Taycan to achieve 140+ mph whereas Tesla can only achieve such speeds on their AWD vehicles where each motor is at a different gearing. At lower speeds in a Model S I believe the car is FWD, only under high power request does power mostly shift to the beefy RWD motor. Of course a Taycan starts from 3x the price of an ID.3 so costing of the gearbox is less important!

The original Roadster was nearly offered with a two-speed gearbox too, but it was found to grenade under the silly torques that the electric motor produced.

 

[Orrery]

The gears in the GTE are there really there because the car has an engine which requires a gearbox so may as well take advantage of that...

I think it is there because VW make DSG gearboxes and want to milk their investment in the technology before is declines. I can see no other justification for fitting such a technically complex device where it just isn't needed.

There are much more elegant gear arrangements for hybrids, from people like Toyota and Mitsi.

 

[GTEowner]

To add I think it can definitely be a lot more responsive driving it in manual EV mode, as the DSG can take a decade to switch gears under certain circumstances, when really with the motor doing the work I just want it to pull as hard as it can in this gear and not waste time trying to change - though I wouldn't actually bother changing gears with the paddles, the advantage is to prevent it from changing gear and accelerating quicker when you want some oomph.

 

[GTEowner]

There are much more elegant gear arrangements for hybrids, from people like Toyota and Mitsi.

They are lifeless as hell to drive though - might as well bite the bullet and go full EV, GTE can actually be quite fun on the right roads.

 

[TomH]

I was very annoyed when the gearbox on my Golf GTE refused to let me manually select second gear when trying to pull away on ice.

It insisted on starting off in E mode too so all choice in the matter was removed.

How do all those Americans manage in snow with their automatics?

 

[tom66]

I think it is there because VW make DSG gearboxes and want to milk their investment in the technology before is declines. I can see no other justification for fitting such a technically complex device where it just isn't needed.

There are much more elegant gear arrangements for hybrids, from people like Toyota and Mitsi.

Toyota have extensive patents on their HSD system. When Ford implemented their hybrid truck, they licenced the tech from Toyota. VW probably did not want to do that for a PHEV that is roughly a conversion of an ICE Golf.

 

[GTEowner]

I was very annoyed when the gearbox on my Golf GTE refused to let me manually select second gear when trying to pull away on ice.

What are you trying to achieve, you have effectively absolute control of the torque you're putting down in EV mode in any gear, though don't get me wrong, I'd like to disable first gear totally in EV mode!

 

[TomH]

What are you trying to achieve, you have effectively absolute control of the torque you're putting down in EV mode in any gear, though don't get me wrong, I'd like to disable first gear totally in EV mode!

Trying to apply power ever so gently. Second gear is a well known trick to do that with a manual ICE.

In a single geared BEV you will be starting off in, perhaps, third gear equivalent anyway.

 

[cdlb]

Trying to apply power ever so gently. Second gear is a well known trick to do that with a manual ICE.

Eco mode is useful for this.

 

[cdlb]

I think it is there because VW make DSG gearboxes and want to milk their investment in the technology before is declines. I can see no other justification for fitting such a technically complex device where it just isn't needed.

There are much more elegant gear arrangements for hybrids, from people like Toyota and Mitsi.

Of course that's the reason. Hybrids are a stopgap technology, there is no motivation for VW to develop their own CVT (or whatever) when they can just pull a DSG out of the cupboard.

 

[TomH]

Of course that's the reason. Hybrids are a stopgap technology, there is no motivation for VW to develop their own CVT (or whatever) when they can just pull a DSG out of the cupboard.

CVT may be a "better" answer technically, but most people don't like the resulting disconnected engine noise. The DSG works pretty well so, as you say, why reinvent the wheel?

I think that eco mode is good idea for icy starts in principle. In practice I got a set of Crossclimate tyres but traded in the car last December. So never tried them on ice.

 

[tom66]

In reality the 'go' pedal on a GTE or any EV is directly controlling the torque so there is absolutely no reason to use 2nd gear over 1st.

In an ICE you have a clutch in most cases that has to slip to regulate torque, having the car in 2nd gear may give you better torque control at the low end and when the clutch is fully released the output torque will be lower. From my experience in snow driving the GTE is markedly worse at handling low speed when the engine must run (e.g. low battery) compared to pure EV operation.