Driving Economically.

Lum

I think you misunderstand the situation I'm describing.

15-20 cars can get through each time the lights cycle to green. There's about 40-50 cars in front of me and who knows how many behind.

So I'm asking about the most economical way to close the gap up front when the green cycle happens.

Hintza

I do most of these until I have old Strider on my tail, then all reason flies out the window.........:rotfl::rotfl:

no_more_cards_for_me

Overtake all the car drivers as you cycle up the outside of all the cars in the queue until you get to the front.

Opps, sorry misread your thread, i'll get my coat

Joe_Horner

Lum wrote: »

I think you misunderstand the situation I'm describing.

15-20 cars can get through each time the lights cycle to green. There's about 40-50 cars in front of me and who knows how many behind.

So I'm asking about the most economical way to close the gap up front when the green cycle happens.

Think I've got ya now.

Try to judge it so you stay stationary long enough that, when you do move, you can move at your car's minimum "comfortable" speed (ie: not slipping the clutch but not kangarooing) and just catch up with the car ahead as it stops again.

Joe_Horner

no_more_cards_for_me wrote: »

Overtake all the car drivers as you cycle up the outside of all the cars in the queue until you get to the front.

Opps, sorry misread your thread, i'll get my coat

Oops, sorry, was just opening my door to see what the delay was.... :rotfl:

JimmyTheWig

Lum wrote: »

Hypothetical situation here. You're in a really long queue at a red light. There is absolutely no way you will be getting through on the next cycle.

Is it best to

a) Put the car in first (or D) and take your feet off all pedals, just using the car's natural creep and leave it like that until it's time to stop again

b) Accelerate, but not as much as the car in front, creep in 2nd gear

c) Accelerate to the same speed as the car in front, then lift off, the gap will gradually increase as you coast in gear then close up again when the car in front brakes.

Obviously A and B only really apply to diesels and automatics. I've experimented with all three but haven't been able to come to a conclusion.

You obviously want to slow down without using the break to stop just behind the car in front.
But how to speed up?
From the OP's second point to know about your car, I'd say you want to do whatever you can to stay within the "power band of your car". Which would probably be more like (c).

TrickyWicky

Lum wrote: »

Hypothetical situation here. You're in a really long queue at a red light. There is absolutely no way you will be getting through on the next cycle.

Is it best to

a) Put the car in first (or D) and take your feet off all pedals, just using the car's natural creep and leave it like that until it's time to stop again

b) Accelerate, but not as much as the car in front, creep in 2nd gear

c) Accelerate to the same speed as the car in front, then lift off, the gap will gradually increase as you coast in gear then close up again when the car in front brakes.

Obviously A and B only really apply to diesels and automatics. I've experimented with all three but haven't been able to come to a conclusion.

I leave it in drive with snow mode on sometimes - foot off the brake and the car very gently moves forward with no revving required.

Lum

It would be pretty much impossible to reach the power band of my car in that situation, what with it being a 2.0 6cyl turbo auto.

I was always told that for economy, aim to keep the boost gauge pointing at around -0.4 bar.

Delivery_Driver

Good points, also disagree on #7 though.If you floor it and use high revs, there's more friction and more heat.Even if you only rev to the same, temps are going to climb more quickly and ECU's generally add in extra fuel to cool the charge in these the conditions, meaning some just gets spat right out through the exhaust unburnt.
Plus it can put you into conflict with other road users as someone may be lining you up for an overtake or you catch someone in front up too quickly and have wasted fuel.

If you were on a nice, flat, straight, long road with no other traffic then sure, flat out to whatever speed and then just lift off will probably only not use that much more fuel as doing it smoothly up to the same speed.Driving on roads isn't like that though.

Delivery_Driver

Lum wrote: »

It would be pretty much impossible to reach the power band of my car in that situation, what with it being a 2.0 6cyl turbo auto.

I was always told that for economy, aim to keep the boost gauge pointing at around -0.4 bar.

People often say keep in the powerband for maximum efficiency but I don't think its always the case.I'm guessing your powerband is 3500-6500 on your car assuming a standard nissan turbo.Now why on earth would someone need 200+ bhp to crawl along in traffic?You probably need 10 bhp(maybe less) to move along nicely in traffic so no boost required and tickover would do that nicely.
Keeping in the powerband also means more revs and more wasted heat, its not necessary most of the time.Plus on turboed cars its like having 2 different engines in and out of boost but then you already know that.
This is someone who can get nearly 40mpg from an awd car with nearly 400bhp on the motorway.