MG4 Air-con & Under tray update

[Deleted member 10041]

Oh that's a good one, didn't you know it's actually part of the gearbox cooling system designed to drag cold air in over it

 

[Nobbyplopps]

Oh that's a good one, didn't you know it's actually part of the gearbox cooling system designed to drag cold air in over it

So it’s not a racing under spoiler?

 

[Rolfe]

Jeez, that is not good enough.

 

[Kithmo]

I wonder if any other makes have misfitting undertrays ?

 

[PristDean]

Apparently the new message is that it's designed to save your licence by creating a parachute effect and slowing you down. So we should all be grateful to the great Lord of the Under tray warps and bulges at MG towers.

 

[Kithmo]

I might stick a harmonica in mine

 

[PristDean]

I might stick a harmonica in mine

I'll follow behind and we can play .... name that tune !

 

[Emgie 4]

Out of curiousity can anyone who's had their undertray fixed/replaced comment on whether they actually noticed any tangible improvement in range/efficiency?

Asking from perspective of someone who does mostly motorway journeys (80%) so hoping any small aero gains might help, also as I'm based in Ireland m--way limit is 120kmh (75mph) which makes eff a little worse - and before all the abuse starts,, I know it's a limit not a target and do go a good bit slower when traffic levels and my schedule allows, (just FYI many Irish M-ways are only 2 lanes so if busy, slower drivers really become a PITA)

On the aero point I prob didn't fully consider the slightly reduced range quoted for Trophy vs the LR I'd imagine is based on mixed driving, since I'm mostly at higher speeds I reckon it's having proportionally greater effect- sorry I'm kinda straying into a Range thread

 

[Nobbyplopps]

Received my MG4 yesterday with an undertray bulge/warping. Booked in to get sorted. 2 weeks minimum wait as I have to give 2 weeks notice for a replacement car. To anybody who has had their undertray sorted, roughly how long does it take for the dealership to receive the new undertray and to fit?

 

[PristDean]

Out of curiousity can anyone who's had their undertray fixed/replaced comment on whether they actually noticed any tangible improvement in range/efficiency?

Asking from perspective of someone who does mostly motorway journeys (80%) so hoping any small aero gains might help, also as I'm based in Ireland m--way limit is 120kmh (75mph) which makes eff a little worse - and before all the abuse starts,, I know it's a limit not a target and do go a good bit slower when traffic levels and my schedule allows, (just FYI many Irish M-ways are only 2 lanes so if busy, slower drivers really become a PITA)

On the aero point I prob didn't fully consider the slightly reduced range quoted for Trophy vs the LR I'd imagine is based on mixed driving, since I'm mostly at higher speeds I reckon it's having proportionally greater effect- sorry I'm kinda straying into a Range thread

Yes, had mine replaced last week and I do a weekly mainly motorway journey of 90 miles round trip. Before the replacement I was seeing an average of 4.3 M/Kwh (miles per Kwh), post replacement I am seeing 5 M/Kwh for that journey.
Car setup otherwise is exactly the same and driving style is the same too.
I am certain, in my view, that is has a detrimental effect on aerodynamic efficiency of the car. The Trophy spoiler puts a downward force at speed on the car (rear stability) which creates some drag, a warped under tray which in effect, air scoops, will add to that downward force and drag too.

 

[PristDean]

Received my MG4 yesterday with an undertray bulge/warping. Booked in to get sorted. 2 weeks minimum wait as I have to give 2 weeks notice for a replacement car. To anybody who has had their undertray sorted, roughly how long does it take for the dealership to receive the new undertray and to fit?

You should be able to sit and wait.... unbolt, remove, fit, bolt up.... unless a bit of tweaking is required. But still won't take long

 

[Emgie 4]

Yes, had mine replaced last week and I do a weekly mainly motorway journey of 90 miles round trip. Before the replacement I was seeing an average of 4.3 M/Kwh (miles per Kwh), post replacement I am seeing 5 M/Kwh for that journey.
Car setup otherwise is exactly the same and driving style is the same too.
I am certain, in my view, that is has a detrimental effect on aerodynamic efficiency of the car. The Trophy spoiler puts a downward force at speed on the car (rear stability) which creates some drag, a warped under tray which in effect, air scoops, will add to that downward force and drag too.

Brilliant, that's good to hear, I'm really hoping when I get mine it gives a good improvement as my current figures are pretty bad, average of 3.2M/Kwh , never since new has it gone over 4, and I've almost 3000miles done,
This figure seems lower than most are seeing on this thread
My commute is similar to yours with 90mile roundtrip mostly m-way but I typically do it 3 times a week (wasn't sure if yours was once weekly or every day of the week)
I reduce speed whenever possible with traffic volumes but unless I go below 50mph the improvement seems minimal
Note I've converted my figures to mph for clarity but obviously they're normally in km

 

[PristDean]

Brilliant, that's good to hear, I'm really hoping when I get mine it gives a good improvement as my current figures are pretty bad, average of 3.2M/Kwh , never since new has it gone over 4, and I've almost 3000miles done,
This figure seems lower than most are seeing on this thread
My commute is similar to yours with 90mile roundtrip mostly m-way but I typically do it 3 times a week (wasn't sure if yours was once weekly or every day of the week)
I reduce speed whenever possible with traffic volumes but unless I go below 50mph the improvement seems minimal
Note I've converted my figures to mph for clarity but obviously they're normally in km

My journey is just once a week. As a note, my car is set to ECO with 'Adaptive' for the regen. Adaptive gives the best drive feel and enables the car to roll more freely which is best on motorway journeys.
If you use the same with a replaced under tray i'm sure you'll see an improvement.

 

[Emgie 4]

My journey is just once a week. As a note, my car is set to ECO with 'Adaptive' for the regen. Adaptive gives the best drive feel and enables the car to roll more freely which is best on motorway journeys.
If you use the same with a replaced under tray i'm sure you'll see an improvement.

Great, I think I've tried that setup but will try it again, thanks, and hopefully will get new tray soon - which reminds me I must ring dealer

 

[jpk]

I've not really monitored my undergrad since taking delivery last month, is there a central rear jacking point on the subframe rather than jacking each side individually on the pinch welds

 

[Richmorr]

Had the car since June and purposely never checked the under tray … living in blissful ignorance but just had a look and yes it is there but doesn’t look as bad as some others I’ve seen on here.

 

[Rolfe]

That's about the same as mine. Still not good.

 

[siteguru]

Mine is also pretty much the same, except mine's towards the offside rear wheel rather than nearside.

 

[Rolfe]

I think it's deceptive. The apparent side can change depending on which side of the car you crawl under.

 

[siteguru]

No - I guarantee that my undertray's bulge is the other side of the car.

http://www.siteguru.co.uk/MG4/Undertray.jpg