Parking Head First And Reversing Out

[square1]

OK, I don't know an awful lot about car mechanics, I think I understand about engine temperature, but if reverse gear is the same size as first, why does reversing out use up more fuel? I want to really understand this but I'm yet to read or hear an explanation that hits the nail on the head. I know it's arguably safer in any case but I want to know purely from a fuel economy perspective. Danke.

[FROSTYBALLS]

Unless you reverse for long distances, I doubt whether there is a huge difference.

Most cars will be aerodynamically less efficient when they are reversing.

[Raistlin]

I found that after I have reversed about thirty miles from home it does have a marginal effect on the amount of gas used....

[FROSTYBALLS]

... but not on the other drivers you've approached

[Red Yaris 54]

OK, I don't know an awful lot about car mechanics, I think I understand about engine temperature, but if reverse gear is the same size as first, why does reversing out use up more fuel? I want to really understand this but I'm yet to read or hear an explanation that hits the nail on the head. I know it's arguably safer in any case but I want to know purely from a fuel economy perspective. Danke.

It certainly is not safer and in most circumstances is illegal to reverse from a residential driveway onto a road

It would be interesting to know why you feel that reversing out uses more fuel and how you measured this.

Driving out forwards is a better option as it allows you to change up gears faster and allows your car to be driven as it was intended :)

[Truthseeker]

OK, I don't know an awful lot about car mechanics, I think I understand about engine temperature, but if reverse gear is the same size as first, why does reversing out use up more fuel? I want to really understand this but I'm yet to read or hear an explanation that hits the nail on the head. I know it's arguably safer in any case but I want to know purely from a fuel economy perspective. Danke.

Strange post, and not sure what to make of it.

[square1]

In response to Red Yaris and Truthseeker, I should have included the link below which is the source of my confusion on this.

http://news.bbc.co.uk/1/hi/wales/7511266.stm

My garage compound is very tight with a ******* surface and I suppose I'm trying to settle of the question of which is the most fuel efficient between a long reverse with a warm engine and a short reverse with a cold engine.

[Raistlin]

Driving out forward it always better than reversing out, not forgetting that it can be illegal if its on to a main road.

[Truthseeker]

I read the BBC post, but am struggling to agree with it's conclusions of (up to) £100 a year saving. Anyway, I always reverse into a parking bay when on a road, not to save money, but it is so much safer (and legal of course).

[Cyker]

Hmm, apparently the whole article is based around the fact that petrol engines use more fuel when cold and that doing all those slow speed manoeuvres when cold uses more fuel (As opposed to just driving off and warming the engine up faster), and not because reverse gear itself uses more fuel.

However, the whole article feels a bit off to me, esp. when it goes on to say that this only applies to petrol, not diesel. Us derv drivers know that diesel engines are MUCH worse than petrol when cold, so surely it'd apply more for diesel cars and not less if true!

[Wiz201]

But you need to reverse into a space in the first place so doesn't that cancel out the saved fuel by driving out forwards? When I go to Sainsburys I drive in forwards and reverse out. I'm not very confident at reversing into spaces, so I find it easier to reverse out. But I park on the road side at home so that's ok, and at work I get in the car park so early I can drive through a space to end up facing forwards.