10 replies to this topic

[mariner]

Autocar has now done over 6,000 road tests since it's birth and has now updated the procedres as here 

 

https://www.autocar....tocar-road-test

 

Two things strike me 

 

- They are going to test acceleration of EV's at 10% charge, as they do get slower at low charge. I understand the point raised here earlier that the lower acceleration is probably due to battery management but if a car changes its ablity to safely overtake as the "fuel  tank" gets empty I do think that is worth reporting on.

 

- I was surprised at Autocar's implication that mfrs are cutting back on physical brakes as regen. does the braking but that is in line with Formula E trying to delete the rear brakes on its cars..It wil be interesting to see if the new fade test shows up any loss of braking capacity 

[BRG]

So no more toiling up the hills at Millbrook in favour of the pan flat MIRA.  Not sure that is a step forward.

[mariner]

Ia ma ctually surpisedd tht teh UK stil ahs two testing grounds given how few new cars are designed here.

 

 

ilbrook has been through several owners 

 

https://en.wikipedia..._Proving_Ground.

 

The "collection of historic documents link at the bottom has lots of detail but be warned it is listed  by chrome as non secure 

Edited by mariner, 29 September 2024 - 09:45.

[BRG]

Millbrook used to be used for an annual rally but that seems to have lapsed since 2009.  I recall it was VERY expensive to hire the place.

[mariner]

It is ironic, or maybe typical of the company back then , that GM built a proving ground full of tricky up and down turns and used it to develop Vauxhalls with the most dull handling of any Uk car .

 

Lotus and Jaguar used the flat MIRA and produced the XJ6 and the Elan etc.

 

The local Warwicksuire and Norfolk back roads probably played a role too 

[Greg Locock]

PGs in UK, Millbrook, Hethel (only one circuit), Gaydon, MIRA, Solihull (low speed off road), Bruntingthorpe, Leyland, there are probably others and of course you can hire many racing circuits. I've used the first 4.

 

All cars are developed on public roads as well, our facilities guys copy bits of road that are especially annoying - including one high speed merge that regularly gets real drivers into trouble (I don't know the details of that one). We also have a big database of speedhumps which may explain why some cars don't seem unduly bothered by them. Ahem.

Edited by Greg Locock, 29 September 2024 - 11:27.

[mariner]

Brungtingthorpe actualy closed in 2020 or so.

 

https://www.autocar....-bruntingthorpe

 

Greg, you might be amused to know that a US car magazine   published one of those " world's greatest driving roads" articles which mentioned the usual suspects like the Great Ocean Road but ibcluded the roads of Norfiolk around Hethel on the basis that if they helped develop so many Lotuses they must, logically be great driving roads too!  Sadly most are 50 mph limited so it would be difficult or any test driver needing to keep their licence to use them at 60 - 70 mph.

[Greg Locock]

They aren't particularly good roads for testing on, they are just convenient. John Miles found a bit of road he thought was ideal for setting the shock absorbers up on Elan, so we spent many hours driving up and down there, to the bemusement of the local farmer. The less said about speed limits the better.

[404KF2]

LOL at regen in lieu of decently sized brakes.

 

We had a Peugeot 508 SW Hybrid (PHEV) a year ago in France for a tour and it could recharge not only the buffer hybrid battery but also the plug in battery using regen, if the descent was long enough.

 

So.....

 

We drove up Sierra Nevada above Granada and of course the PHEV battery was well depleted even before we got to the bottom. At the top, and once the descent began, I used cruise control to limit the car to the speed limit and as it's about 2000 m vertical, the cruise would hold the car's speed at the set limit using the regen. However, about 8 km from the bottom, the car suddenly started to run free and I had to use the service brakes to control the speed. The PHEV battery was not full - it had about 60% charge when this happened. What I think happened was the circuitry was overtaxed trying to cope with the shunting of energy back to the battery and it reached a critical temperature threshold and stopped. After about 50 km the regen started working again. The brakes were up to snuff so this did not prove to be a problem.

 

So imagine descending the Großglocker Hochalpenstrasse in your EV and having this phenomenon arise partway down, needing the service brakes, but gosh darn it, they're undersized units suitable for a 2CV and so the brake fluid boils and you're in a spot of bother.

 

I mention that alpine pass because in 1986 on the way back from Greece in a brand new Renault 5 TC, despite engine braking, the service brakes had to be used on corners and the brake fluid boiled near the bottom.... 

[BRG]

Regen is great, but yes, on a long descent you can fill up the battery and then suddenly find there is no retardation available.  Fortunately, my Clio has good normal brakes as well.

[Greg Locock]

I can imagine a cautious car company bringing the vehicle to a halt if the battery is fullish and is in a hill descent. That will take some explaining.