[KCTalksEV]

Scrolling through Ebay, come across this for the LEAF: https://www.ebay.co.uk/itm/Nissan-L...l:Leaf&hash=item287bae207a:g:XHYAAOSwC19bJSfe

I looked underneath my vehicle the other day and noticed significant open space, especially under the engine bay and rear suspension. I'll see if I can take some photos later today. I've been thinking whether it's worth looking into bespoke acryllic or other plastic sheeting to create a flat bottom, and clear wheel covers.

Obviously I'm not an aerodynamicist (funnily enough I do know a few) but better aero at higher speeds (55mph+) must be a positive, even with the additonal weight? Not to mention, avoiding curbing the wheels is a plus for me at least as the car is significantly larger than my old supermini and I want to be able to park without risk of curbing IMO the good looking alloys (when you go from steel wheels to alloys). I have an inkiling that SAIC made no changes from the ICE, and given the MPG they probably didn't factor aero into that design either, whereas at least the LEAF and Ioniq to name a couple put some thought into it.

I would question the 15% (!) efficency gain the seller mentioned, and IMO £560 for some acryllic and a OBD2 scanner seems a bit steep. Thoughts?

 

[davesul]

Might be interesting to ask for comments from owners in the LEAF forum to see if there is any positive reaction there...

I came across an online report on reducing the drag coefficient of the Tesla M3 which explained just what could be achieved, by apparently minor re-sculpturing. The low drag coefficient of the standard vehicle of about 0.23 could be reduced to about 0.2 by modifying the front and rear spoilers which corresponds to about 13% reduction. Changing the ride height with different springs also could give further reduction.

So for the MG ZS there could be scope for reduction of the drag coefficient, which I suspect has a value of around 0.33 - 0.35.

 

[Sandy]

No Frickin' way..... I thought it was only the ZS EV that has open spaces underneath. lol

 

[Paul M]

I too have mentioned this. I was thinking of doing some tests using strong cling-film across the front grill and fog lights to make them smoother, and some sort of underbody kit to smooth the air flow, or a front valance to stop air from getting underneath.

 

[Paul M]

https://www.speakev.com/threads/aerodynamic-modification.133974

 

[Gerbro]

I think that an aerodynamic "nose" that fits into the lip of the grill would make a significant difference.

Trouble is that access to charging would be compromised.

 

[Dan Newso]

Theres an under engine tray for the ICE engine bay on alibaba and aliexpress, prices between £20 and £200 though!

 

[Graham toyn]

I think that an aerodynamic "nose" that fits into the lip of the grill would make a significant difference.

Trouble is that access to charging would be compromised.

What about a giant red nose on the front.lol😂

 

[dk6780]

The aero pack being sold for the LEAF is solving a different set of issues than exist with the ZS. The LEAF has known issues - the lower grille intake which is unnecesary in the UK, the wheels with unnecessary holes and a completely smooth underside apart from the area around the rear beam axle.
The airflow under the ZS is completely unmanaged so there is much more to do there than a relatively small fix under the rear axle. The air let into the front of the ZS is less controlled than the LEAF, so blocking a single point of entry may be detrimental rather than helpful - someone needs to be the guinea pig. The wheels are a good call for improvement, but the use of plastic discs on the outside is not the ideal solution IMHO. For the LEAF you can 3D print "plugs" called LEAF Petals to block the holes - something could be developed for the ZS.

 

[KCTalksEV]

The aero pack being sold for the LEAF is solving a different set of issues than exist with the ZS. The LEAF has known issues - the lower grille intake which is unnecesary in the UK, the wheels with unnecessary holes and a completely smooth underside apart from the area around the rear beam axle.
The airflow under the ZS is completely unmanaged so there is much more to do there than a relatively small fix under the rear axle. The air let into the front of the ZS is less controlled than the LEAF, so blocking a single point of entry may be detrimental rather than helpful - someone needs to be the guinea pig. The wheels are a good call for improvement, but the use of plastic discs on the outside is not the ideal solution IMHO. For the LEAF you can 3D print "plugs" called LEAF Petals to block the holes - something could be developed for the ZS.

The pack protrudes from the bottom of the unibody by a couple of inches. If an engine undertray was made to fit fully under and attached to the front of the pack, then another underbelly panel at the rear to go under the axle may help aero a lot.

In terms of the front bumper, I don't think anything can be done significantly that won't affect the (IMO) good look of the front. I've seen mockups of it on the FB group and I would rather keep that the same, plus airflow is important to the A/C condenser.

 

[dk6780]

Managing airflow through the engine bay is likely to be more important than managing it under the car. I don't agree that you need to let the amount of air into the engine bay that is currently the case, nor do blanking plates need to be flush to the front of the hole to be effective.
Don't forget that the ZS was not a purpose designed EV, and that ICE have considerably greater quantities of heat to reject. Finally, cars are tested in places like Death Valley rather than the somewhat cooler UK.

 

[Favguy]

The pack protrudes from the bottom of the unibody by a couple of inches. If an engine undertray was made to fit fully under and attached to the front of the pack, then another underbelly panel at the rear to go under the axle may help aero a lot.

In terms of the front bumper, I don't think anything can be done significantly that won't affect the (IMO) good look of the front. I've seen mockups of it on the FB group and I would rather keep that the same, plus airflow is important to the A/C condenser.

Taking into account the moderate UK climate, I doubt closing the front grille would have much of an effect on cooling. Most of it is effectively closed by the huge charging flap arrangement in any case and there is reasonable airflow provided by the lower grille. I'd expect the only effect would be the cooling fan coming on a little sooner in extreme use and this would then suck air up and through the centre of the radiators from the lower grille area as needed.

 

[davesul]

There is some interesting information here, illustrating the change of Cd predicted for a generic saloon car shape, with variations of front spoiler. See Figures 11 to 14 inclusive.

https://www.jvejournals.com/article/19210/pdf

 

[dk6780]

If you study the management of air from the engine bay to the outside on cars like LEAFs you'll see that a lot of care is needed rather than just "shoving on a stone guard" designed for an ICE variant for protection.

 

[Favguy]

Unlike the bad old days of ICE ownership when higher MPG meant significant differences to running costs, I personally find it hard to get too interested in efficiency improvements on an EV. A whopping 20% improvement to the current ZS range would save me about 50p per week, utterly trivial. Also my Electricity is from 100% renewables, so not worried on the pollution score much either.

 

[dk6780]

Good point. Now if you had an old LEAF24 you might suffer range anxiety and still be looking for every extra mile that you could achieve.

 

[Favguy]

Good point. Now if you had an old LEAF24 you might suffer range anxiety and still be looking for every extra mile that you could achieve.

I do still have a strange compulsion to maximise range, don't like to see the average drop below 4.0 mpkWh if I can help it! lol

 

[dk6780]

Blimey, I'd be range suicidal at only 4.0 m/kWh.

 

[Boatgeek]

I don't know how you guys drive, or whether you live on a pancake, but I am chuffed when it doesn't say 3.1 - 3.3 if am honest. Only ever got 4 once and that was stuck behind a lorry on a single carriageway wiggly road past the Belfry.

 

[dk6780]

Mine's a LEAF24 so a different beast. Think yourself lucky that you don't have an Audi eTron that struggle to get 2.5 m/kWh.

Three miles per kWh...?...my eTron wouldn't do that downhill with the wind behind it if I got out and pushed! You'll have to try harder than that to be the least efficient EV going I'm afraid...😉