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JulianEdgar · 04-18-2021, 05:38 AM

TBH, I wonder a bit if people even understand my argument.

Let's put it this way.

1. We have a ICE vehicle. We measure cooling drag by blocking the cooling intakes (a little more to it than that, but that will do for now) and measuring the change in Cd. We then compare that change in Cd with the overall Cd. From that we get cooling system percentage of overall Cd.

2. We then do exactly the same with a BEV. It doesn't have to be the same car in ICE and BEV forms - that's not even particularly relevant as both overall Cd and cooling drag are likely to have changed between the two car versions.

I have seen ICE cooling drag figures from less than 1 per cent to 14+ per cent. The only BEV figures I have seen are 8 and 16 per cent.

So to say it all again:

I've noticed that a few people here seem to believe that the cooling system drag of battery electric vehicles is very low, or even zero.

I don't think that is right.

In the research for my upcoming book on car aerodynamic history, I've looked at the percentage cooling drag of the Tesla Model S and the Porsche Taycan.

The Tesla's cooling drag calculates at 8 per cent, and the Taycan's at 16 per cent.

Obviously, these - and other modern cars - can decrease that when cooling isn't needed by closing shutters. But the fact remains that cooling drag on electric cars appears to be similar, or even greater, than on traditional internal combustion engine cars.

I didn't say...

... that a battery electric vehicle needs to dissipate as much heat as a internal combustion engine car.

I said that the proportional drag of the cooling system appears to be at least as high, if not higher, in battery electric cars as it is with internal combustion engine cars.

I'd love to see some other figures on the measured cooling drag proportion of some other BEVs.

04-18-2021, 05:38 AM	#127 (permalink)
JulianEdgar Banned Join Date: Nov 2017 Location: Australia Posts: 2,060 Thanks: 107 Thanked 1,605 Times in 1,136 Posts	TBH, I wonder a bit if people even understand my argument. Let's put it this way. 1. We have a ICE vehicle. We measure cooling drag by blocking the cooling intakes (a little more to it than that, but that will do for now) and measuring the change in Cd. We then compare that change in Cd with the overall Cd. From that we get cooling system percentage of overall Cd. 2. We then do exactly the same with a BEV. It doesn't have to be the same car in ICE and BEV forms - that's not even particularly relevant as both overall Cd and cooling drag are likely to have changed between the two car versions. I have seen ICE cooling drag figures from less than 1 per cent to 14+ per cent. The only BEV figures I have seen are 8 and 16 per cent. So to say it all again: I've noticed that a few people here seem to believe that the cooling system drag of battery electric vehicles is very low, or even zero. I don't think that is right. In the research for my upcoming book on car aerodynamic history, I've looked at the percentage cooling drag of the Tesla Model S and the Porsche Taycan. The Tesla's cooling drag calculates at 8 per cent, and the Taycan's at 16 per cent. Obviously, these - and other modern cars - can decrease that when cooling isn't needed by closing shutters. But the fact remains that cooling drag on electric cars appears to be similar, or even greater, than on traditional internal combustion engine cars. I didn't say... ... that a battery electric vehicle needs to dissipate as much heat as a internal combustion engine car. I said that the proportional drag of the cooling system appears to be at least as high, if not higher, in battery electric cars as it is with internal combustion engine cars. I'd love to see some other figures on the measured cooling drag proportion of some other BEVs.