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Old 04-11-2019, 09:18 PM
ngcles's Avatar
The Observologist

ngcles is offline
Join Date: Dec 2006
Location: Billimari, NSW Central West
Posts: 1,571
Hi Gary,

Originally Posted by gary View Post
Hi Les,

The graph shows speed versus energy consumption per mile.

They state :-

In a nutshell the graph shows that the faster you go the more energy you use.

There is nothing new here. We are all familiar with exactly that with
our petrol driven cars. The faster we go, the more fuel we use.
No, I'm not confused, you've got it right and I'd contend you are in furious agreement with me. The faster you go in an electric over a set distance, the more energy you consume.

The reverse applies (up to a point) in a petrol/diesel because they have gearboxes. As you have conceded, an electric uses much more "juice" at highway speed than in suburban/urban speeds. This precisely is my point. However your contention that petrol/diesel vehicles use also use more fuel the faster they go is incorrect.

My 2012 2.5 litre diesel Mitsubishi Triton uses about 10.5 litres per 100km in city driving but that drops to less than 8.5 litres per 100km in the bush. That's an increase in fuel efficiency of about 20%. This is pretty much the same as all petrol/diesel vehicles. The reality is that as engine RPM rises (not speed per se) diesel/petrol fuel consumption increases. But conventional vehicles use gearboxes to they are being propelled quickly for comparatively low RPM.

Again, I'm not here to compare diesel -v- petrol -v- electric. All I am trying to point out, and you have helped prove, is that at highway speeds, the amount of "juice" you use in the Tesla (and nearly all electric vehicles) goes up and range consequently goes down compared to city driving.

Unless you are going to do your highway driving at 60kmh in the Tesla, you are going to use more "juice" on the open road per kilometre than in the city and consequently there is a reduction in range -- possibly up to 50% 60kmh -v- 100kmh.

They seem to have overcome one of the problems with electric vehicles with this new fast-charging tech. But, there are several others that need to be addressed before they can become truly mainstream.


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