Do you change down gears before stopping at traffic lights?

[Keith Oates]

If the road is flat or has a small rise then I don't change down but I usually stand on the pedals when the lights turn to green to get up to speed quickly and it's good training for the legs IMO.!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[Tanis8472]

I was actually taught in my driving test specifically not to do this - the engine will only stall if you come to almost a complete halt and then try to pull off, otherwise being at lower revs isn't a problem. According to my driving instructor, driving in a higher gear than the speed needs (e.g. 4th or 5th gear for 30mph) actually means the car uses less petrol because you're using less revs... thereby saving both money and the environment, hurrah. Also sparing the gears on the car.
Often when I'm slowing down to a junction I just disengage the gears completely and coast in on the clutch.

Of course if you want to pull away, manoeuvre or suddenly accelerate you then have to change, but if you're just driving along normally and aren't intent on overtaking people, then that's how they teach it now... or at least when I did my test in 2009!

Modern electronic injection does not any fuel if foot is off the throttle and coasting in gear.
You are using fuel when clutch is in as engine is running.

 

[Feastie]

Modern electronic injection does not any fuel if foot is off the throttle and coasting in gear.
You are using fuel when clutch is in as engine is running.

Yeah sorry didn't mean to imply I thought otherwise on that bit! Was a separate comment to what I'd said above, sorry for confusion.

 

[Dan B]

Modern electronic injection does not any fuel if foot is off the throttle and coasting in gear.
You are using fuel when clutch is in as engine is running.

If your foot is off the throttle and the clutch is in, why is the car giving you any more fuel than it would be if the gear was engaged?

 

[raleighnut]

If your foot is off the throttle and the clutch is in, why is the car giving you any more fuel than it would be if the gear was engaged?

Modern electronically triggered injectors shut down completely when you lift your foot off until the ECU detects that the revs have fallen to tickover then they start to supply fuel again, unlike older systems and carburettors.

 

[Dan B]

Thanks - so not to do with the clutch per se then, but engine speed.

Sound like block changing is more fuel efficient then in that case, as you spend more time in gear and less time cycling down through the gears with the wheels disengaged

 

[mjr]

Anyone else noticed that some modern car engines have very little inertia, so engine braking is ineffective. I wish they'd get on and equip more with regenerative braking!

 

[donnydave]

Anyone else noticed that some modern car engines have very little inertia, so engine braking is ineffective. I wish they'd get on and equip more with regenerative braking!

Yep - our 20 year old car slows down more just by lifting off then some of the new cars I drive at work (hire cars) do with light braking. In fact in my other car (even more effective engine braking) I sometimes just lightly touch the brake pedal to show the brake lights even though I'm not actually using the brakes, just so it doesn't surprise people approaching from behind

 

[gaz]

View: https://www.youtube.com/watch?v=mpz_e5uwfM8


Of course, the right gear selection when stopping means you have the right gear to accelerate from. I'm usually in the small ring at the front and the second biggest at the back. Quick gear changes and you can accelerate away from the lights faster than pretty much all cyclists. In the above video I wasn't out of the saddle once.

 

[Dan B]

How big is top gear, in this context?

Twice as tall as the distance from top to middle

 

[Tynan]

Yes, I don't enjoy trying to pull away in a gear that's comfortable at 17mph

 

[Supersuperleeds]

Yes, I don't enjoy trying to pull away in a gear that's comfortable at 17mph

The gears must be about the only things that work on your bike

 

[400bhp]

Forget to change down. Lift rear wheel off ground and flick the gears down a couple.

 

[KneesUp]

I don't often, and never really have. Perhaps a function of only riding bikes with bar end shifters or downtube shifters.

 

[Exile]

I'd say I do about 90% of the time, but often go too far so end up spinning a bit. The other 10% of the time I would like to be forget/am distracted/slammed on and end up in whatever gear I was cruising in. In fact, it's probably almost 20% of the time now. One disadvantage of having to use to motorcycle for a while is you become used to changing gears when stationary. You only try that once on the pedal bike before the gods-awful clunk reminds you not to be a fool. Until the red light five minutes later, at least.