Motorway Miles Madness

[Headgas1]

Hi all I hope everyone’s well & looking forward to summer !!! I have just got back from a holiday in Devon & I have noticed that every time I do any motorway driving the predicted mileage drops dramatically for example I had 85 miles left in the tank and I drove 25 miles at 70mph which dropped me to 35m in the tank where did the other 25 go ?
I have noticed this a few times so why is there such a dramatic drop when you go over 60mph on the motorway????

 

[Eclectic]

It happens to all cars, you just notice it more on EV's. It's mainly because air resistance (drag) increases as the square of velocity, hence much more power needed to go the same distance than at a slower speed.
The best trade off between range and time seems to be about 65mph

 

[drmcw]

Speed kills! One of the victims is efficiency as air resistance increases with the square of the speed.

 

[Mihir]

Did you have HVAC on?

 

[Ozzie1989]

Did you have HVAC on?

Power draw from HVAC would be the same at any speed (give or take a tiny amount of heat/cold lost through body transfer).

The difference here is drag, rolling resistance etc. as people have already mentioned and is why the OP is noticing it at higher speeds.

 

[jds1972]

Hi all I hope everyone’s well & looking forward to summer !!! I have just got back from a holiday in Devon & I have noticed that every time I do any motorway driving the predicted mileage drops dramatically for example I had 85 miles left in the tank and I drove 25 miles at 70mph which dropped me to 35m in the tank where did the other 25 go ?
I have noticed this a few times so why is there such a dramatic drop when you go over 60mph on the motorway????

Hi all I hope everyone’s well & looking forward to summer !!! I have just got back from a holiday in Devon & I have noticed that every time I do any motorway driving the predicted mileage drops dramatically for example I had 85 miles left in the tank and I drove 25 miles at 70mph which dropped me to 35m in the tank where did the other 25 go ?
I have noticed this a few times so why is there such a dramatic drop when you go over 60mph on the motorway????

Ev is the exact opposite to an ICE car, the slower you go in an EV the less power you use and thus more range. At motorway speeds you will be using more power and thus less range, don’t forget that the 85 miles it was showing is a guesstimate based on previous journeys and not a guarantee, wind resistance etc also has an effect as previously mentioned also.

 

[Lovemyev]

It happens to all cars

ICE cars included.
Fuel consumption at 60 Mph vs 75 Mph and there is a big reduction in economy.
Maybe not as much as an EV, but never the less, more fuel is being burnt.
Higher RPM's effectively mean the engine is working harder.
Back in the day all manual cars had 4 speed gearboxes, this increased to 5 gears, then to 6 gears.
Reducing the RPM's of the engine via the stretched gear ratio's.
When the first five speed gearboxes where introduced, at lot of they where running with the same engine unit.
A quick way to increase the MPG by dropping the RPM's of the engine, in order to consume less juice.
When cruising, the aim was to keep the engine RPM below the 3,000 mark.
Above this figure and the fuel consumption drops quite significantly.
The extra gear was a quick fix to improve the fuel consumption figures.
But then the majority of ICE drivers I have seen driving on the motorway networks, don't give this much or any consideration at all to be honest !.
In many cases they are carrying around a massive surplus of fuel in the tank and pay no attention to their fuel consumption figures.
Maybe a lot of the really fast drivers are burning fuel, that has been paid for by the company they are employed by !.
I love it when somebody driving aggressively, who is hell bent on over taking us, they scream past and then when we get around the corner and they are stuck at a set of traffic light on red.
They must see me just shaking my head, as I pull up along side them !.
I am not that keen on hospital food myself.
It's buggers like that, who help increase my insurance premium each year.
I do get a bit feed up of supporting these type of aggressive drivers year after year myself

 

[Headgas1]

Thanks I think I get it now Still loving the car just don’t understand all its nuances yet

 

[Archev]

ICE cars included.
Fuel consumption at 60 Mph vs 75 Mph and there is a big reduction in economy.
Maybe not as much as an EV, but never the less, more fuel is being burnt.
Higher RPM's effectively mean the engine is working harder.
Back in the day all manual cars had 4 speed gearboxes, this increased to 5 gears, then to 6 gears.
Reducing the RPM's of the engine via the stretched gear ratio's.
When the first five speed gearboxes where introduced, at lot of they where running with the same engine unit.
A quick way to increase the MPG by dropping the RPM's of the engine, in order to consume less juice.
When cruising, the aim was to keep the engine RPM below the 3,000 mark.
Above this figure and the fuel consumption drops quite significantly.
The extra gear was a quick fix to improve the fuel consumption figures.
But then the majority of ICE drivers I have seen driving on the motorway networks, don't give this much or any consideration at all to be honest !.
In many cases they are carrying around a massive surplus of fuel in the tank and pay no attention to their fuel consumption figures.
Maybe a lot of the really fast drivers are burning fuel, that has been paid for by the company they are employed by !.
I love it when somebody driving aggressively, who is hell bent on over taking us, they scream past and then when we get around the corner and they are stuck at a set of traffic light on red.
They must see me just shaking my head, as I pull up along side them !.
I am not that keen on hospital food myself.
It's buggers like that, who help increase my insurance premium each year.
I do get a bit feed up of supporting these type of aggressive drivers year after year myself

I know a couple of folk who still insist on only using the four gears that they passed their driving test with and never use these new fangled “motorway” gears.