Coasting Legality in the UK

[colonelk]

Hi there,

I did try a search on this subject but didnt dig anything up.

Google turns up lots of people who think leaving a car in gear is more fuel efficient than coasting and this page from the DVLA.....

Section 122 of the Highway code:

Coasting. This term describes a vehicle travelling in neutral or with the clutch pressed down. It can reduce driver control because
-engine braking is eliminated
-vehicle speed downhill will increase quickly
-increased use of the footbrake can reduce its effectiveness
-steering response will be affected, particularly on bends and corners
-it may be more difficult to select the appropriate gear when needed

SO as far as I can tell, they are just saying be more cautious if you coast?!

Anyone know for sure? Also what about engine off coasting?

Thanks for your help!

Mark

[RobertSmalls]

That particular section doesn't appear to prohibit or establish fines for coasting.

I don't know about the UK, but I believe it's illegal to coast with the engine off in my jurisdiction, even though my car is programmed to do exactly that below 20mph.

Feel free to ignore any laws that are not helpful to society and are utterly unenforcable. If they are enforcable, it's fun to comply with the letter but not the spirit of the law, like so:

[Devon Hynes]

UK Driving Licence Checks | Licence Checking | Driving Licence Verification Service from Licence Check

Not something listed as an offence the cop I guess could charge you with MS60 if anything. If they defined it as dangerous driving (DD40) that would limit the number of insurers that would cover you for the next 5 years and your premium increase would neglect any savings.

[MadisonMPG]

Don't worry about it, they can't enforce it.

[user removed]

In Virginia the law against coasting in neutral goes back to the 1930's when Plymouth came out with a freewheeling option. It was a one way clutch that allowed you to coast without having the engine and transmission engaged to the propshaft and differential.

The problem was in the mountains you could not disengage the freewheeling option unless you had come to a complete stop. This meant on long downhill grades the marginal brakes of the period could overheat easily and you were doomed.

Most hybrids, especially the Prius under certain circumstances have the wheels disengaged from the engine and motor, so it would seem like it would be very hard to convict anyone of violating the anti freewheeling law, if another car does it automatically.

Modern brakes also make the likelihood of loosing your brakes on long downgrades very slim.

regards
Mech

[Bicycle Bob]

Ahh, there's nothing like a mile-long downhill coast, in traffic, staying within a car-length of where I'd be under power, and without a touch on the brakes to satisfy a mellowing old rebel driver. Vice is the spice of life, even when it is only illegal, not disruptive.

[user removed]

Or a 3 mile stretch downhill coming back from Blacksburg, behind a big rig, and having to use DFCO to keep it below 80 MPH in my VX, or regen in the Insight.

regards
Mech

[colonelk]

haha thanks guys!

This thread came out of a 'disagreement' with my parents about the legality of it, I was never planning on giving up coasting, and I was more curious about engine off coasting too as I plan to do that in the future when Ive got my eye in

I also like to know where I stand regarding things (its great when you know more than the police, Ive learnt that with my other cars! Obviously not rubbing it in their faces)

Ive worked out that a good % of where I drive could easily work with the engine off

Mark

[dcb]

I tend to ignore "legal" threads myself Things are locale dependant anyway and it gets tiresome explaining to "armchair cops" who think they know what is "best" for the world. Not many of those here today.

I will look at my local/state/federal regulations and If I don't find something specifically prohibiting what I want to do then it is fair game. Even if it is called out, I do have a "that is way out of touch and unenforceable" filter.

You are of course always responsible for the safe operation of your vehicle, and make sure you can control it with the engine off (lose power steering and brakes if you had them, and don't lock the steering column (see "kill switch")) or for whatever mod/technique you are trying. I have practised in deserted areas prior to joining traffic, and continue to test my ability to stop and turn without power assist when traffic is light.

I also don't talk on the cellphone while driving or engage in other distractions. I do take my role and responsibility to be a safe driver very seriously.

[colonelk]

Yeah believe me safety is high on my list. I will be very careful Im planning to get rid of the power steering anyway (dont need it, its only got 175 width tyres on, plus this model had both assisted and non assisted models, so just need to find someone breaking one) which gives me the double whammy of less parasitic drain on the engine and no change in steering control when the engines off. Also looking to 'upgrade' the brakes at the same time as removing the vacuum assist, again so the car drives the same regardless of whether the engine is on or off

Would only be done through a kill switch too

I agree its very locale based, I was hoping there were enough UK people on this board to help me out

Ive done a couple of tests on a very open, quiet stretch of road but am not happy with the cars handling with the engine off yet