Batteries : MG4 SE SR versus Trophy LR

[Roger001]

Me awaits @Rolfe .......

That is exactly how the MG4 feels compared to an MGB.

 

[gary333]

Sure a spoiler can be a useful styling exercise, but no manufacturer adds weight to a car in the form of a spoiler that does nothing to reduce the cd factor. That's even if it's just by one or two points. Gary, think about that for a moment.

If you think for a second that all car manufacturers are designing cars based on optimal engineering principles then you are living in cuckoo land unfortunately.

Plenty of detailed articles going back decades showing that many car rear spoilers are not reducing drag but quite the opposite. Plenty of manufacturers publish this data in their Tech sheets themselves.

 

[Data]

At Longbridge?

No.

If you think for a second that all car manufacturers are designing cars based on optimal engineering principles then you are living in cuckoo land unfortunately.

Plenty of detailed articles going back decades showing that many car rear spoilers are not reducing drag but quite the opposite. Plenty of manufacturers publish this data in their Tech sheets themselves.

Not sure who is living in cloud cuckoo land here Gary. But it doesn't sound as if you know much about modern car engineering. Today, it's all about optimal engineering. And yes indeed, I was someone that actually part wrote the manuals for car & motorcycle manufacturers so I know about the spec side of things. I cannot speak for all manufacturers of old but trust me, no manufacturers over the last 20yrs fits a spoiler if it's just for show. If it's an aesthetic enhancement it always has to have a cd benefit too. It's actually a rule of engineering. Getting more efficiency/range is critically important, with manufacturers going to quite extreme measures to achieve this, some even breaking the law to get what they want (VW). It has to have a cd benefit. Everything is all about getting best range whether it's ice or EV. Aero-dynamics is particularly important.

I'd be very interested to know where you are seeing this plentiful evidence about car rear spoilers NOT reducing drag & actually increasing it. There are differences in spoilers of course, some fitted to aid braking, some for anti lift while others are for aesthetics. But all have to have some amount of cd reduction. Some spoilers are purely for cd reduction.

Anyway, nice to hear your opinions Gary. Bye for now.

 

[Bam Bam]

I'm not an engineer, but always thought that rear spoilers were to add downforce and improve grip, which would reduce efficiency.

I noticed that if you look at the most efficient EVs they don't tend to have rear spoilers and instead are very curved.

https://ev-database.org/uk/#group=vehicle-group&rs-pr=10000_100000&rs-er=0_500&rs-ld=0_500&rs-ac=2_23&rs-dcfc=0_300&rs-ub=10_200&rs-tw=0_2500&rs-ef=150_600&rs-sa=-1_5&rs-w=1000_3500&rs-c=0_5000&rs-y=2010_2030&s=8&p=0-10

The Tesla 3 has a sort of spoiler-y thing I suppose, but it is nothing like the one on the MG4, which I was led to believe (perhaps wrongly) was aesthetic and did not improve efficiency.

 

[Data]

I'm not an engineer, but always thought that rear spoilers were to add downforce and improve grip, which would reduce efficiency.

I noticed that if you look at the most efficient EVs they don't tend to have rear spoilers and instead are very curved.

https://ev-database.org/uk/#group=vehicle-group&rs-pr=10000_100000&rs-er=0_500&rs-ld=0_500&rs-ac=2_23&rs-dcfc=0_300&rs-ub=10_200&rs-tw=0_2500&rs-ef=150_600&rs-sa=-1_5&rs-w=1000_3500&rs-c=0_5000&rs-y=2010_2030&s=8&p=0-10

The Tesla 3 has a sort of spoiler-y thing I suppose, but it is nothing like the one on the MG4, which I was led to believe (perhaps wrongly) was aesthetic and did not improve efficiency.

Hi Bam Bam, yes it's all very interesting this spoiler thing. Spoilers are used for a number of reasons but primarily (in most cases) to improve efficiency especially of vehicles with less than ideal aerodynamics. My own ZS EV has a spoiler above the rear window. It's sole purpose is to reduce drag by improving the cd figure. My car is essentially brick shaped so the spoiler helps somewhat. It has no other real purpose. It certainly doesn't shield the rear screen from road spray & dirt but it may help a little. And that is the same for the majority of cars on the roads. It doesn't necessarily need to be a big 'wing' type as on the MG4 & thus can melt into the car design almost unnoticed. The MG4 spoiler is designed to stand out & help efficiency at the same time. How much extra efficiency it provides is the question.

 

[Roger001]

I'm not an engineer, but always thought that rear spoilers were to add downforce and improve grip, which would reduce efficiency.

I noticed that if you look at the most efficient EVs they don't tend to have rear spoilers and instead are very curved.

That is the point of adding a spoiler to the more brick-shaped cars (such as the MG4). Its job is to improve the air flow over the back.

The thing is that the low air pressure zone found at the back does not just cause one effect. Instead, it causes drag and lift, so any added spoiler added is designed to do the best it can to reduce one or both issues. If the spoiler is providing downforce, this just means it was designed to overcompensate for lift.

 

[Everest]

I'm not an engineer, but always thought that rear spoilers were to add downforce and improve grip, which would reduce efficiency.

But all have to have some amount of cd reduction.

My 2p worth would be that different manufacturers / models use them for different reasons. On performance vehicles they are required to add downforce, especially at higher speeds, despite efficiency reductions. On slower and more energy critical vehicles, such as EV's they will be primarily to reduce drag.

Whilst not wanting to add a flame to the touchpaper of this thread, I have to disagree with our honourable member who claims to know all about the 'spec side of things' saying "all have to have some amount of cd reduction". If that were the case then a) Audi would have added a spoiler to the original TT, rather than adding it as a recall because the vehicles were found to be unstable at high speed; and b) our 996 and 997's were equipped with motorised spoilers which only raised at 75mph and back down at about 55mph. I'd suggest that the engineers at Porsche wouldn't have added the complexity and weight of the motors if said spoilers had a beneficial improvement of cd, rather than just downforce at high speed.

 

[Data]

Yes, without getting over complicated, you are perfectly correct in that different cars use spoilers for different purposes just as I eluded to in one of my earlier posts. Based upon your above comments you perhaps are not understanding why spoilers are fitted. But you are not adding flame to the touch paper either. Down force & braking spoilers often retract partially or fully dependant on purpose as they only get used for the purpose intended. However an aero dynamic advantage is often still available when only partially retracted & of course no aero advantage is required when a spoiler is deployed for braking other than sometimes some down force. But that in its self is an aero dynamic advantage by increasing cd, not reducing it.

I also have here & in other threads eluded to the fact I was a tech & engine design engineer for years working with the folks that actually design cars. That was imperative that we worked together on parts of the project. Aero dynamics affects the engines so the whole car is developed as one piece so everything works together, if you see what I mean. Therefore I learned a considerable amount about aeros, including spoilers. I wrote the manuals on engines & transmissions for the products we made. I never said I was an expert on aeros but I know a thing or two from wind tunnel testing that we did on countless cars. I can repeat, respectfully most folks don't understand how spoilers work or why they are there. And that's ok, why would they! The reasons can be multiple. But folks can of course believe what they wish to believe. That's all fine.

 

[OriginalBigAl]

I reckon the spoilers are there for kerb appeal and as a extra inducement to part with more money for the higher spec model. An instantly visible ,recognisable addition which raises your social status.
Like the old L, GL, GLS badges.

 

[Anon70]

I thought at speeds under 60mph spoilers were there as picnic tables

 

[Data]

Anon, yes indeed that is correct. You are obviously an engineer!

 

[MG Clive]

I thought at speeds under 60mph spoilers where there as picnic tables

Ahh yes, the picnic table, lol Picnic Tables, Aerodynamics and the Girl | ViaRETRO

 

[Everest]

Ahh yes, the picnic table, lol Picnic Tables, Aerodynamics and the Girl | ViaRETRO

They don't make them like the used to, do they... the cars, not the girls, that is

 

[tsedge]

I intend to buy a Trophy LR because of the heated steering wheel, rear speakers, and faster DC charging speeds (although this may prove to be inconsequential in reality) however there is one thing that is niggling at me which I don't think will change my decision but I still would be interested in people telling me if my thinking is flawed which is are the batteries in the real world less different than they appear in terms of range.

The heated steering wheel is really nice but it was the 360 camera that swung it for me, making parking a doddle. Now I know some of our members are/were professional drivers so the idea of using any form of parking assistance maybe anathema!

Yes, the LR charges faster, I see up to 135kW when the charger supports it in summer. However, the charger rarely supports it and that is a peak, so above 65% it drops to around 80kW or so.

In practice there's not a lot of difference in the charging times for SR or LR especially for those who are happy driving the SR to <10%.

Did I need the range? I thought I did, because it was my first EV but because I have home charging I would say "no". I think if I didn't have home charging I'd prefer the longer range. But 95% of my journeys are less than 50 miles anyway, so it really makes little difference.

So it's recommended to keep the NMC battery found in the Trophy between 20-80% but okay to charge to 100% if going a long trip. I am looking at this and thinking...

1. Daily local drives: battery choice is irrelevant although if operating NMC from 80-20% then LFP will need charged less often but can take more full cycles.
2. Long Drives: if doing 100-20% for NMC (Trophy LR) then LFP on 100-circa 7% gives the same range.

So the Trophy LR battery's advantage is that you could (at the expense of additional battery stress) run further by going below 20%. It doesn't look like there is a large advantage on battery of the Trophy's NMC LR battery over the SE SR battery. It looks like pros and cons that seem to suggest that a future improved LFP battery may end up in later MG4 Trophy LRs. What do you think? Is my logic flawed? Would removing the spoiler from the Trophy make things look much better? How about the SE versus Trophy tyres? Thoughts please...

I would ignore the battery/range differences and base your decision more on price vs equipment.

Before anyone says anything, I am aware the original post is a year ago, I am posting this for other people who might have a similar decision to make now.

 

[GaryMG4]

Similar to @tsedge 2 odd years ago I thought I needed the range, heated seats and steering wheel but my longest frequent trips are about to the coast, around 40 miles each way. I do the odd 170 mile round trip to ski at Snozone, but there enough chargers around if needed. I did want an integrated sat nav and decent ACC. Interestingly we plan to take the 71 plate Niro2 (poverty spec.) away on holiday later this year, but the wireless car play works faultlessly and we won't need the heated seats so it will be interesting to see how it works out.

 

[Archev]

I thought at speeds under 60mph spoilers were there as picnic tables

Not the case with the Berlingo as it’s about six feet off the ground - useless as a picnic table so obviously fitted to enhance the in flight stability I reckon.

It fails.

 

[Anon70]

I guess if you do this, then the spoiler on a Berlingo is a tea tray

 

[Archev]

I guess if you do this, then the spoiler on a Berlingo is a tea tray

View attachment 39047

It’ll never fly