LED headlight bulb

cymruchris

killerferret666 said:

Also to add dependant on vehicle it could fail the MOT.

https://www.gov.uk/government/publications/special-notice-01-21-headlamp-conversions/mot-special-notice-01-21-headlamp-conversions

Good point yes:

Section 4.1.4 of the current MOT inspection manuals for both motorcycles and cars and passenger vehicles states ‘Existing halogen headlamp units should not be converted to be used with high intensity discharge (HID) or light emitting diode (LED) bulbs. If such a conversion has been done, you must fail the headlamp.’

killerferret666

sevenhills said:

user1977 said:

It's "free" to the extent that you're generating it by using excess energy from the engine which was already running anyway.

So garages that use compressed air and a compressor could get "free" electricity from it, because it's running anyway?
Nothing is free. Why is it stated that MPG goes down so much in the winter?

two bigger things than electric use (generally).

Biggest is warming up the car and defrosting screen on driveway... Thats at 0mpg and makes a big difference. 

Also cars take longer to warm.up.in the cold so more friction, oil is thicker for longer etc...

sevenhills

killerferret666 said:

sevenhills said:

user1977 said:

It's "free" to the extent that you're generating it by using excess energy from the engine which was already running anyway.

So garages that use compressed air and a compressor could get "free" electricity from it, because it's running anyway?
Nothing is free. Why is it stated that MPG goes down so much in the winter?

two bigger things than electric use (generally).

Biggest is warming up the car and defrosting screen on driveway... Thats at 0mpg and makes a big difference. 

Also cars take longer to warm.up.in the cold so more friction, oil is thicker for longer etc...

But engines are cooled down because they get too hot, so the cold weather will mean it's easier to run at their ideal temperature.
It's very complicated.

sevenhills

killerferret666 said:

sevenhills said:

user1977 said:

It's "free" to the extent that you're generating it by using excess energy from the engine which was already running anyway.

So garages that use compressed air and a compressor could get "free" electricity from it, because it's running anyway?
Nothing is free. Why is it stated that MPG goes down so much in the winter?

two bigger things than electric use (generally).

Biggest is warming up the car and defrosting screen on driveway... Thats at 0mpg and makes a big difference. 

Also cars take longer to warm.up.in the cold so more friction, oil is thicker for longer etc...

My side lights will be a technical fail, because they are only 1w and not 5w
A quick Google shows LED headlight bulbs to be £50+
I wouldn't want brighter head lights, but I might consider them, if it saved money.

killerferret666

sevenhills said:

killerferret666 said:

sevenhills said:

user1977 said:

It's "free" to the extent that you're generating it by using excess energy from the engine which was already running anyway.

So garages that use compressed air and a compressor could get "free" electricity from it, because it's running anyway?
Nothing is free. Why is it stated that MPG goes down so much in the winter?

two bigger things than electric use (generally).

Biggest is warming up the car and defrosting screen on driveway... Thats at 0mpg and makes a big difference. 

Also cars take longer to warm.up.in the cold so more friction, oil is thicker for longer etc...

But engines are cooled down because they get too hot, so the cold weather will mean it's easier to run at their ideal temperature.
It's very complicated.

Operating temperature is the key. Engines highest wear rate and friction is at start up before they get to this temperature. So take longer because of the cold weather to get to it. Its also why oil has two ratings 5w-40 for instance, Relating to the velocity and how that helps lower friction and wear but the thinner it is the more it may sneak past seals.

Once at this temperature, the cooling method to be at the operating temperature makes no difference, the wear and friction rates on the engine are the same as the operating temp range is the same no matter the ambient temperature. The high friction lasted longer before it got to it.

The cooling system wont be under as much strain in the winter but thats the only benefit, the engine wont run easier, just the cooling system wont be at its high limits.

Unless you really want to get technical about getting more fuel at the petrol station based on volume density at different temperatures.

cymruchris

sevenhills said:

killerferret666 said:

sevenhills said:

user1977 said:

It's "free" to the extent that you're generating it by using excess energy from the engine which was already running anyway.

So garages that use compressed air and a compressor could get "free" electricity from it, because it's running anyway?
Nothing is free. Why is it stated that MPG goes down so much in the winter?

two bigger things than electric use (generally).

Biggest is warming up the car and defrosting screen on driveway... Thats at 0mpg and makes a big difference. 

Also cars take longer to warm.up.in the cold so more friction, oil is thicker for longer etc...

My side lights will be a technical fail, because they are only 1w and not 5w
A quick Google shows LED headlight bulbs to be £50+
I wouldn't want brighter head lights, but I might consider them, if it saved money.

And if you had them - it would be an mot failure - so you’d not be road legal. 

Bigwheels1111

Peugeot 5008 1.6 bluehdi auto.
The biggest savings I get is from speed reduction.
Ive done the same journey 3 times now.
Home to Blackpool and back again, with 100 miles worth of local short trips and cold starts over the week.
At 70 mph on the motorway up and back I got 45 mpg for the 800 trip.
At 62 mph on the motorway I got 54 mpg. 20% rises in fuel efficiency.
I will be going again in around a month, a straight up and back with no local trips.
I’m hoping to get 56 - 58 mpg.
The one thing I noticed about the trip was that most of the other cars on the motorway were doing around 60 mph.
No one racing past me etc.
Shows how the fuel price is affecting driving habits.

facade

Bigwheels1111 said:

Peugeot 5008 1.6 bluehdi auto.
The biggest savings I get is from speed reduction.
Ive done the same journey 3 times now.
Home to Blackpool and back again, with 100 miles worth of local short trips and cold starts over the week.
At 70 mph on the motorway up and back I got 45 mpg for the 800 trip.
At 62 mph on the motorway I got 54 mpg. 20% rises in fuel efficiency.
I will be going again in around a month, a straight up and back with no local trips.
I’m hoping to get 56 - 58 mpg.
The one thing I noticed about the trip was that most of the other cars on the motorway were doing around 60 mph.
No one racing past me etc.
Shows how the fuel price is affecting driving habits.

Which is about right.  In theory, the air resistance is the dominant force and is proportional to speed squared.  62MPH is 88% of 70, so the air resistance would be .88 x .88 = 78.4% of that at 70, and therefore you need to use  about 78% of the fuel, which would mean a 22% reduction.

If you drove at a steady 55MPH (78% of 70) you'd use 62% of the fuel, nearly a 40% saving over 70.

(In reality, this won't exactly happen, there are other factors like the engine having a more efficient speed, and as you slow down air resistance becomes a smaller % of the overall force required to move the car)

Grey_Critic

So you changed your sidelights to LED - they are not OE so did you inform your insurance company? They are a modification.

Ebe_Scrooge

diystarter7 said:

sevenhills said:

user1977 said:

Does electricity consumption actually make any significant difference to mpg?

That is my question. You cannot get electricity for free, but what is the cost?
A quick Google shows cars can use 15% more fuel in the winter.
How much would the electricity cost in a domestic home?

Indeed a lot more fuel is used in winter and that is a fact.
I have headlights galore on my car and when I turn the car on in the dark, they do a funny dance in order to align themselves I think, more wasted power.

I try avoid driving in the dark and fog. I also avoid turning on the heater, the heated seats, the rear screen etc
I always try to put my windscreen wipers on the intermittent, slowest setting if safe and appropriate for the aforementioned. I've even deactivated the folding mirrors and the lights inside the car. I'm always ensure unlike most that my car is safe to drive ie clear of snow/mist/rain etc but using my skills use the min amount necessary of wipers/heat etc

The car is equipped with tyre pressure monitor and reader and I ensure they are always at optium levels for fuel efficiency and safety purposes. 

The radio, I do turn that on but a low volume as it uses less power.

I've also get one of those covers on the front of the grill to warm the car up more quickly and save fuel.

Some people may laugh, take the mick, but it makes a difference not just to ones pocket but the environment.

Thanks

This topic crops up every now and again, and as is often the case, there's not a straightforward answer.

Ultimately, anything on a car that uses electricity will increase fuel consumption - the electricity is generated by burning more fuel.  On many cars, if you sit there with the engine ticking over then turn on the heated rear screen, you can notice the engine revs drop ever so slightly, because there's more load being put on the alternator.

But it's a question of degrees.  Things like heated screens and heated seats will draw a fair amount of current.  Radio and windscreen wipers much less.  The heater - the fan that blows hot air into the cabin will take a tiny amount of current, but the heat itself is "free" as such, it's just heat that is generated by the engine anyway and would otherwise be wasted.  So very low-draw items will theoretically increase fuel consumption, but probably it won't even be a measurable difference in the real world.

Tyre pressures - yes, correct tyre pressures can make quite a difference to fuel consumption.  As can your driving style - that's probably the single biggest factor, whether in summer or winter.

Cars do tend to use more fuel in winter.  Firstly, it takes longer for the engine to reach normal operating temperature, so it's running "rich" for a longer period (who remembers the olden days when we had a manual choke lever?).  The roads tend to be wet more often, which will slightly increase rolling resistance compare to a dry road.  And yes, you do tend to have lights, wipers and screen heaters on for more than you would in the summer.

All these things add up - but stuff like deactivating your folding mirrors and only having the radio on low volume will not make any difference in practice.  Yes, like I say, in theory it will, and you could measure the current they use - but I doubt you could realistically measure the extra fuel used to power them.