PHEV at motorway speeds for extended periods

[DeuceDeuce]

I’m trying to understand how these cars work and I sort of understand the range they might give you on pure electric for local journeys but what about longer distances at higher speeds?

Let’s say you leave a French service station with a full tank of petrol and a full battery in your SUV PHEV and then head onto the autoroute for a long slog at 85mph. Does the battery just get exhausted within a few miles leaving you the rest of the journey on the (fairly inefficient) petrol engine or is there a combination of power sources that allow for better mpg over longer cruising distances?

How often would I have to recharge the battery on a long drive through France to make the car work efficiently or is this type of vehicle totally unsuitable?

[paradigital]

Cheshire to North Devon tends to net us high 50s low 60s MPG wise with our Passat GTE Advance.

Seems to equate to around 25-30% “zero emission” driving even over many hundreds of miles, I guess a combination of regen braking and downhill sections, as well as the initial 100% SoC.

You wouldn’t bother charging en-route, just let the car decide when to use the motor vs the engine, and charge at destination. We occasionally shove the car into “charge from the engine” mode when approaching the destination so we can EV around the village, but it makes the MPG plummet, so the actual consumption will likely balance out between the additional 30 miles added to the battery, and the increased fuel consumption en-route whilst charging.

Edited by paradigital on Wednesday 3rd May 20:22

[DeuceDeuce]

paradigital said:

Cheshire to North Devon tends to net us high 50s low 60s MPG wise with our Passat GTE Advance.

Seems to equate to around 25-30% “zero emission” driving even over many hundreds of miles, I guess a combination of regen braking and downhill sections, as well as the initial 100% SoC.

Thanks. In those condition, could you guess at how long before the battery was fully depleted?

[robbieduncan]

We travelled from Disneyland Paris to Harrogate at the speed limit (let’s say 80 on France, 70 in the uk) on a single tank of petrol in a Passat GTE. 452 miles. Tank is 50l/11 uk gallons. Tank was not empty (still had about 50 miles of range). So 41mpg. We started with an empty battery (no where to charge up at DLP)

I was happy enough with that. Not amazing (I’m sure there are plenty of cars that could return over 50mpg) but for us this was a very unusual long trip. Whilst we owned the car we did over half our mileage on electric making it cheap to run

[paradigital]

DeuceDeuce said:

Thanks. In those condition, could you guess at how long before the battery was fully depleted?

It completely depends on how you drive it. I could put the car in EV mode and deplete the battery before even reaching the motorway. Alternatively I could put the car in “battery hold”, which would maintain the current SoC (not charge it) and use the engine only for drive. Then the battery would be available for when I wanted it.

The most efficient use however would be setting a route using the car’s navigation (not CarPlay or Android Auto), and letting it work out (with a combination of throttle input, load, inclination, and navigation data) when best to deploy the battery. This would likely only fully deplete the battery somewhere near the end of the journey. However the battery is never really depleted fully, the car will maintain a small level of charge for assisting the engine at all times, so you never end up in a situation where you have only the engine, and lugging around the hybrid system unused. Add in regen from braking and going downhill and I’m usually surprised at how far into the journey I still have a usable amount of EV assistance available.

[Mikehig]

Aiui the battery would never be fully-depleted because the car relies on it to start the engine, using a starter/generator integrated into the transmission instead of a conventional starter motor.

[JD]

DeuceDeuce said:

Thanks. In those condition, could you guess at how long before the battery was fully depleted?

It's not as simple as that.

If in your hypothetical situation you left the services then sat at a constant 82mph for 5 hours, (and it used the same control strategy as my VAG PHEV) it would likely only ever use the high voltage battery to run the A/C compressor. Leaving you with a decent amount of battery for supplemental acceleration, or low speed or low load situations.

If it was the same as my Mercedes PHEV, then it would flatten the battery in 25 miles, and sit at 1% after that for the remainder of whatever journey barely contributing anything of note.

oh and on your other point, unless its modern one with fast charging (I think only Mercedes and Land Rover so far?) it would never be time efficient to ever charge mid route, and even it it was, it will very unlikely ever be cost effective.

Edited by JD on Wednesday 3rd May 21:44

[djc206]

My RRS P440e would drain its battery pretty quickly at 80, it’s definitely better to use the battery at lower speeds. It’s pretty clever now so you can stick it in hybrid mode, use the cars own sat nav and it will decide when best to use the battery. You’ll also get a fair bit back from regen if the traffic slows you down. In full EV mode it usually gets 50 ish miles, slightly more if stuck sitting at 40-50mph.

You wouldn’t stop to charge a PHEV regularly because they invariably charge quite slowly ie 7kW. The EV part is essentially there to cover urban driving not high speed motorway miles. My car would be st for lots of motorway driving because the petrol engine would probably manage 30mpg tops with the electric covering very little of the journey, for that sort of driving you’d be better with a diesel all day.

[georgeyboy12345]

I drove my Audi A3 e-tron from Manchester to Exeter in early Septmeber last year, so 230 miles. At the end of the journey it had half the battery left and managed 56 mpg.

I went on holiday to North Wales the year before last and depleted the battery by driving around on electric mode a lot. On the motorway heading home around 90 miles with a depleted battery it did 46 mpg.

On downhill sections of motorway it'll cut the ICE completely, and if steep enough, it'll even charge the battery through regen.

I have driven a 5 mile journey across town before with a depleted battery in really heavy stop-start traffic and it managed only 28 mpg! Most the time though I have a full battery and it consumes no fuel at all.

In terms of what I get from the relatively small 40 litre fuel tank, the worst I have got from it was 400 miles, the best 1050 miles (lots of EV city driving).

Note, this is how the VW group PHEVs work - others may be subtly different.

[DeuceDeuce]

Thanks for the responses. I think I’m understanding the technology a (little) but better.

The car we’re considering is the new Velar to replace a petrol Macan that does about 25mpg. It would do about 4k miles of short journeys. About 2.5k miles of c200 mile return journeys and then up to 2k miles twice a year from trips to Europe.

Would you get a hybrid for that usage? I really don’t want a diesel even if it the best option. It’s either petrol or petrol hybrid.

Also, is it possible to find out performance and efficiency figures for hybrid cars that are running only on combustion?
Maybe I’m worrying unnecessarily but I don’t want to be in a situation where I exit the autoroute after a long drive, pull up to a roundabout and find out my previously 5.2 second 0-60 time is now 15 seconds as I pull out in front of a truck.

[TooLateForAName]

Get a test drive and play with it.

The hybrids I've driven all behaved slightly differently and all have several modes. Part of running one is knowing how that all works in the specific model.

[blank]

DeuceDeuce said:

Thanks for the responses. I think I’m understanding the technology a (little) but better.

The car we’re considering is the new Velar to replace a petrol Macan that does about 25mpg. It would do about 4k miles of short journeys. About 2.5k miles of c200 mile return journeys and then up to 2k miles twice a year from trips to Europe.

Would you get a hybrid for that usage? I really don’t want a diesel even if it the best option. It’s either petrol or petrol hybrid.

Also, is it possible to find out performance and efficiency figures for hybrid cars that are running only on combustion?
Maybe I’m worrying unnecessarily but I don’t want to be in a situation where I exit the autoroute after a long drive, pull up to a roundabout and find out my previously 5.2 second 0-60 time is now 15 seconds as I pull out in front of a truck.

Sounds like a fairly decent use case for a PHEV assuming you can charge at home and the daily mileage is within EV range.

Performance in ICE mode should not really change as it's always hybrid and never ICE only.

Performance in EV mode is significantly less so as long as you get a feel for what that is you'll be fine.

[SWoll]

DeuceDeuce said:

Thanks for the responses. I think I’m understanding the technology a (little) but better.

The car we’re considering is the new Velar to replace a petrol Macan that does about 25mpg. It would do about 4k miles of short journeys. About 2.5k miles of c200 mile return journeys and then up to 2k miles twice a year from trips to Europe.

Would you get a hybrid for that usage? I really don’t want a diesel even if it the best option. It’s either petrol or petrol hybrid.

Also, is it possible to find out performance and efficiency figures for hybrid cars that are running only on combustion?
Maybe I’m worrying unnecessarily but I don’t want to be in a situation where I exit the autoroute after a long drive, pull up to a roundabout and find out my previously 5.2 second 0-60 time is now 15 seconds as I pull out in front of a truck.

Assuming you are talking about the Velar P400e then the ICE engine alone delivers 300 of the 400hp available so whilst performance will drop if the battery is low it won't be hugely significant.

Running on petrol alone you'll be looking at 30MPG at best I'd suggest.

[DMZ]

If you're happy to charge the car every day more or less and you do mostly shorter journeys daily, then PHEV will deliver on the efficiency side of things. But you need to put in the effort to charge it to get that benefit.

I've only driven PHEV rentals but I never experienced a performance drop. As mentioned, they keep a small charge in the battery at all times to avoid this. You can also muck about with modes to save battery when you hit slower sections or have the sat nav figure it out but this assumes you start with a full battery which you probably won't on a longer European trip unless you're motivated enough to find a charger en route.

[djc206]

SWoll said:

DeuceDeuce said:

Thanks for the responses. I think I’m understanding the technology a (little) but better.

The car we’re considering is the new Velar to replace a petrol Macan that does about 25mpg. It would do about 4k miles of short journeys. About 2.5k miles of c200 mile return journeys and then up to 2k miles twice a year from trips to Europe.

Would you get a hybrid for that usage? I really don’t want a diesel even if it the best option. It’s either petrol or petrol hybrid.

Also, is it possible to find out performance and efficiency figures for hybrid cars that are running only on combustion?
Maybe I’m worrying unnecessarily but I don’t want to be in a situation where I exit the autoroute after a long drive, pull up to a roundabout and find out my previously 5.2 second 0-60 time is now 15 seconds as I pull out in front of a truck.

Assuming you are talking about the Velar P400e then the ICE engine alone delivers 300 of the 400hp available so whilst performance will drop if the battery is low it won't be hugely significant.

Running on petrol alone you'll be looking at 30MPG at best I'd suggest.

I ran a P400e RRS which is the same setup and that 30mpg is about spot on in my experience. The electric range varied between as low as 12 miles in winter with cabin preheated and everything heated switched on to about 30 miles pottering along in an average 50 zone on cruise control.

The car seems to always retain enough battery for an overdrive function so you always have enough in reserve for all 400PS for an overtake or coming off a roundabout. The regen isn’t great but it does get you enough back for the latter.

The new generation of JLR PHEV are much more refined and the P440e comes with a 3L engine rather than the 2L which makes it smoother and less gravelly sounding although possibly even worse on fuel.

[Pica-Pica]

Surely PHEVs have their own ‘brain’ so that you don’t have to use yours?

[targarama]

I have an old Lexus RX hybrid. I have found accelerating hard to use the electric motor to get to cruise speed asap works best. Then leave the car to do the rest while cruising. Possibly different in newer models, but since electric motors have all the torque seems logical to use it to accelerate.

Also more fun to welly it LOL

[georgeyboy12345]

DeuceDeuce said:

Also, is it possible to find out performance and efficiency figures for hybrid cars that are running only on combustion?
Maybe I’m worrying unnecessarily but I don’t want to be in a situation where I exit the autoroute after a long drive, pull up to a roundabout and find out my previously 5.2 second 0-60 time is now 15 seconds as I pull out in front of a truck.

It won’t be anything like that extreme.

The 0-60 for my A3 e-tron as listed on autotrader is 7.6 seconds. It’s noticeably faster with a full charge - I have measured it at 6.5 seconds to 60.

With a depleted battery, it won’t do a full e-boost so is deploying around 160 bhp instead of 205. It’s certainly still quick enough.

On electric only mode it only has 105 bhp, but 240 lbft of torque immediately on tap so it feels quick off the line. It’ll do 0-60 in something like 9.5 seconds but is actually quicker to 30 than in hybrid mode.

I drove a BMW 330e that had a depleted battery and it gives a warning message about reduced performance, but it still felt rapid when hoofing it.

[stumpage]

My V60 PE drops down to 1mile and then just acts like an HEV. However the battery doesn't stay at 1 mile it seems to go up and down a bit on long journeys. It has never been in a state of charge where I don't get the full beans when needed.

[a311]

I've had an XC90 PHEV for two years, previous car was a V90 T5. Essentially the same engine I believe minus the battery etc.

After 3 years the T5 returned an average 27 MPG the T6 after 20K is return 60 MPG- when I can be arsed it would be worth working out the total cost of ownership of each factoring in economy savings and offsetting the higher purchase price.

>90% of our journeys are within the pure electric range, school runs, trips to the shops and supermarket etc. I believe the newer iteration of Volvo PHEV's are reporting 40+ mile range on electric only.

Longer journeys, I save the charge for low speeds/sitting in traffic and will let the engine charge the battery if cruising on the motorway. The Volvo system is fine but isn't that intuitive to do the latter for you.