heated seats reduce your mpg

[Davidp]

well according to a recent article in the daily telegraph the use of electrical devices in modern cars puts extra load on the alternator and as the engine has to work harder the mpg goes down. Heated seats (popular choice on the new leon) were cited as the worst culprit.

Cant see it myself but wondered if anyone else had come across this argument. Does it really cause the engine to work that much harder to produce more electricity from the alternator?

Cheers, David

 

[Tam]

Yep...

 

[RobM]

Very old news. Same for all cars really, if you wack on the heaters, put the fans on full, wipers on, rear heated screen, radio up so you can hear it above all that and so on, you'll get terrible fuel economy.

The difference one item alone will make is neither here nor there really. But when you have a few things going at once it will make a difference.

 

[Gazza999]

Basic laws of physics I guess.......Thing is heated seats are an absolute necessity for a diesel burner (IMHO).

 

[RobM]

Basic laws of physics I guess.......

Yup, the energy to power these things has to come from somewhere. And the more your engine has to power, the less power goes to the wheels, so the harder it works to keep you plodding along. Very basic terms I know, but you get the idea....

 

[Fl@pper]

whats easier to push :

empty tesco trolley ?

tesco trolley filled with monthly shop approx £300 ?

about the same as your engine is trying to on the alternator belt to cope - i remember the days when a 55A alternator was top wack - you're looking at some cars with 120/150A nowadays and yes that does waste power on turning it

throw in aircon and power steering etc etc - lot of bhp wasted doing day to day luxuries and kickoff is mpg wasted also


"MORE COAL ON THE FIRE"

 

[Davidp]

Thanks Guys,
well accepting the fact that the theory is correct and all this electrical gear efects mpg, if you drove round with all the electrical items on what reduction in mpg would you expect?
If this is old news then has anyone ever put a figure on it.
Cheers

 

[Gazza999]

Thanks Guys,
well accepting the fact that the theory is correct and all this electrical gear efects mpg, if you drove round with all the electrical items on what reduction in mpg would you expect?
If this is old news then has anyone ever put a figure on it.
Cheers

Not too sure of exact figures, but I'm sure I read somewhere that A/C alone can account for upto 10% less mpg?

 

[Davidp]

Not too sure of exact figures, but I'm sure I read somewhere that A/C alone can account for upto 10% less mpg?

I think air con may be a separate issue as doesnt it have its own engine driven pump?. I have compared the effect of air con on both my leons and found a definite reduction in mpg on both models of around 4-5%.

I wonder what keeping your but toasty warm in winter might do to your mpg

 

[Gazza999]

I think air con may be a separate issue as doesnt it have its own engine driven pump?. I have compared the effect of air con on both my leons and found a definite reduction in mpg on both models of around 4-5%.

I wonder what keeping your but toasy warm in winter might do to you mpg

I've got the drivers seat heating on all the time.....just wondering if that's why I can't even get 40mpg...........Nope, thats due to the lead in my right foot, and that awesome 3rd gear ability to pass long lines of traffic

 

[Davidp]

I've got the drivers seat heating on all the time.....just wondering if that's why I can't even get 40mpg...........Nope, thats due to the lead in my right foot, and that awesome 3rd gear ability to pass long lines of traffic

Thanks gazza, so what mpg do you average then with a warm bum and a big right foot?

 

[Gazza999]

Thanks gazza, so what mpg do you average then with a warm bum and a big right foot?

Driving mostly twisty A roads, 80 mile round trip to work and getting just over 38mpg. This compares against a 2.0Tdi 140 Audi A3 (41mpg) and a 2.0Tdi 140 Golf (43mpg). It's the only obvious downside to the increased power of this 2litre engine, but is well worth the price.