PHEV or Hybrid to buy?

RogerPensionGuy

Ganga said:

TadleyBaggie said:

Very happy with my e-Power Qashqai. Drive to the wheels is 100% electric, the petrol motor comes on and off to keep the battery charged. So you get electric performance and petrol range.

I ( maybe wrongly ) thought that converting petrol engine power too electric then too traction power would be a waste of energy as opposed to pure petrol/diesel drive or pure battery drive. 

The Nissan E~Power cars are interesting indeed, see link at the bottom. 

My favourite car in recent times was the BMW i3 Rex, an extreamly environmental built car, has about 140ish miles range on the battery and a small petrol engine plus a 5 litre fuel tank IIRC, very energy efficient and at life end, it can be more easily recycled best as is possible, it's a great car, but comes in EV only or the little Rex engine, Range Extender it was called. 

Mazda have produced something a bit similar, MX~30 pure EV 120ish mile range or a REX, unfortunately Mazda have used a new updated rotary engine as the engine and until that has some real life service history I don't fancy it, plus think the rotary engine isn't very fuel efficient, shame they didn't just put a normal petrol engine in it.
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https://www.brindley.co.uk/news/understanding-nissan-e-power/#:~:text=Extended Driving Range: e-POWER,effective and eco-friendly option.

WellKnownSid

RogerPensionGuy said:

Mazda have produced something a bit similar, MX~30 pure EV 120ish mile range or a REX, unfortunately Mazda have used a new updated rotary engine as the engine and until that has some real life service history I don't fancy it, plus think the rotary engine isn't very fuel efficient, shame they didn't just put a normal petrol engine in it.

I worked on a project in 1991/92 based upon using a rover gas turbine running as a serial hybrid.  The point was it was useless as a conventional power source (idle speed was something like 30,000rpm) but because you were always able to extract full power for most of the time you could drag the efficiency right up.

Conclusion was that it was best suited to any vehicle under maximum acceleration most of the time, which our thermodynamics lecturer suggested would therefore make 'an ideal student car'... 

I can certainly see benefits in using a rotary, especially as a computer will be in charge of the throttle which could instantly offer a 2x wear improvement over conventional rotary powered cars.  Bit late to the game though.

Goudy

In the case of these cars that use ICEs as on board power stations, you have to forget about the engine producing torque to drive the gearbox/wheels.

What one type of engine used to do when driving the wheels is no longer that relevant.

It just needs to be able to turn a generator to produce enough electricity efficiently as possible.

Most hybrids run a normal reciprocating engine in a simulated Atkinson cycle instead of a normal Otto cycle as it doesn't produce a lot of torque but tends to be more efficient, but that's not the only way.

A rotary in this instance wouldn't be such a bad idea as there's less moving parts, there's no cam or cam drive sucking up power and can have little pumping losses.

They are generally much smaller than a reciprocating engine and much lighter and again don't produce lots of torque.

When fitted as a straight ICE they do have their issues as they tend to require lots of rpm to get them to move so are driven quite hard. That tends to cause wear and chamber sealing issues.

In a hybrid system like the Mazda, you would get the benefits of a small, light and efficient engine without it actually driving the wheels. It would just need to fire up and spin a generator quickly, something it should be very good at.

Perhaps we might see 2 stroke diesel engines as on board power stations? They been used like that for over a century already.

Btw, BMW used one of their scooter engines for the Rex system. It wasn't changed to run an Atkinson cycle, so is pretty inefficient as a generator engine by todays standards.

RogerPensionGuy

Tks all posters here, very interesting stuff.

Of interest I was chatting to some MG and BYD sales staff, they also saying customers are wanting Hybrids more than previously, think BYD are launching their 1st UK Hybred next week, them BYD EVs have good range, but they starting Hybrid sales here.

Now lots of press about the new solid state EVs coming in a few years will really hit the current EV models, I guess the current EV makers will just continue to flood cheap EVs to all their favourite outlets like fleets and taxi networks. 

Reference rotary engines, 40 years ago I read they would take over from typical 4 & 2 stroke engines. 

Rotary engines just never appeared to find their place in cars, 2 strokes tried a bit and then weny by the weyside, was it SAAB and Wartburg tried it a bit. 

Getting back the the MX~30 PHEV battery with a Rotary REX, I asked a few Mazda people and they said trying to operate car on the engine alone, it would use a lot of fuel and from a maintenance cost viewpoint, it's not designed to operate like that. 

I'm surprised we don't see an EV with a super efficient rotary that just operates for very short times making electricity. 

Maybe I'll do my bit for the environment and just keep my current car as that's by far the best environmental way to go for me and many people I guess. 

Lets not even mentioned silly scrappage schemes that crushed very environmentally serviceable cars.

WellKnownSid

RogerPensionGuy said:

Now lots of press about the new solid state EVs coming in a few years will really hit the current EV models, I guess the current EV makers will just continue to flood cheap EVs to all their favourite outlets like fleets and taxi networks. 

...

Maybe I'll do my bit for the environment and just keep my current car as that's by far the best environmental way to go for me and many people I guess. 

Lets not even mentioned silly scrappage schemes that crushed very environmentally serviceable cars.

Solid state has been talked about for a while, Toyota has been particularly vocal, but I'm not sure that it changes anything.  In theory it will devalue current EVs - but we bought our EV almost a year ago - an 11 month old car with under 3k on the clock for 60% off RRP.  Solid state was a huge thing when we bought the car - even had friends telling us not to buy our car because it 'would be worthless this time next year'.

Today I can buy a 2 year old example of our car with 25k on the clock (double our current mileage) for the price we paid.  Solid state is still a big thing.  Life goes on, we're still ahead having driven around in a car which (pound for pound) achieves over 300 miles per gallon in old money.

Keeping your current car until you get a driveway might be very sensible choice - then see what's on the market at the time, things are moving fast.

Iceweasel

Please explain the maths behind "300 miles per gallon in old money".

WellKnownSid

Iceweasel said:

Please explain the maths behind "300 miles per gallon in old money".

Petrol locally = £1.33 / litre x 4.55 = £6.05 per gallon.  £6.05 / 8p/kWh = cost of one gallon buys 75.625kW electricity * 4.4m/kWh = 332 miles for the price of a gallon of petrol

MattMattMattUK

Personally I take the view that EV is either an all or nothing option, go full EV or stay with pure petrol, a hybrid is the worst of both worlds. 

EV - Highly efficient, low mechanical complexity, has vastly reduced servicing and maintenance costs and offers amazingly low operating costs. Full cycle TCO is the lowest of the bunch.

Petrol - Middling efficiency, average servicing and maintenance costs, average mechanical complexity, full cycle TCO is middling.

Hybrid - Middling efficiency if driven in a cycle that matches it's design spec, high servicing and maintenance costs, high mechanical complexity, TCO is lower if driven in lots of stop start traffic, other than that it will be higher.

PHEV - Low efficiency due to lugging around a large battery, a heavy engine and a fuel tank. Higher servicing and maintenance costs. If charged at all opportunities and drive on short runs then TCO can be average, slightly better than a bog standard hybrid, if never charged, or only charged infrequently efficiency is awful, the battery becomes a dead weight and the TCO is by far the worst of the bunch. 

The only reason people might take an PHEV is because of the tax benefits, but even in that situation they would be better going with an EV and unless they do a huge amount of miles likely still lower overall going with petrol. 

RogerPensionGuy

I like the PHEV idea as it often runs around town on electric which is a nice way to drive and environmentally friendly locally I guess, obviously me having a PHEV or EV is generally not environmentally friendly.

Reference a post previously of a year old EV at 60% of RRP is a dynamic sucking me towards a much cheaper hi spec EV much  much less than the often silly RRP, years back I so nearly purchased a BMW 635 brand new at 60% off new RRP and brand new, it/they were higb spec, but I just didn't like the shape too much, dealer later told me they reduced price to 55% of RRP and obviously shifted them all.

If I was a gambler, I would buy a Fisker very cheaply, but it's too big for what I want, if they were smaller maybe I would buy a nice new Fisker @ 18K or less. 

Polestar are off loading some much much % off RRP cars that were plated a few months ago and parked up somewhere, still a bit too big for what I want and they have a few issues that I wouldn't want and especially when the three year guarantee is ended.

I'll keep looking and if something pops up very cheap & hi spec, I'll buy it I guessing.

I like the Kia EV3 for size and spec, but still too new for them to pump them out cheaper. 

born_again

TBH, while I like the Fisker. I would not touch them. Given the co went bust. You have no warranty, or ongoing upgrades to systems (known issues with these) 
Parts can be a issue going forward. Especially if you have a crash. As no one will be making panels.