Free wheeling in your car

I’m a fan of getting that extra mile out of a tank of petrol (well diesel… but ya know), and as such have been known to allow my car to freewheel up to lights… I mean come on… surely freewheeling (despite the illegalness) has to be the most efficient… right?

Well it turns out… NO…

If you take the car out of gear, the engine needs a little fuel so it doesn’t conk out. If you leave it in fuel the idea is that the engine is kept going by the inertia, and so doesn’t need fuel.

So its like this, if you are going to free wheel for a very long way… then it will make sense. If it’s a shorter distance like up to the lights, then leave the car in gear. The engine will actually take energy out of the wheels to keep going, and so use less fuel. It will also slow the car a bit, and so you’ll need less breaks… do the savings ever end?

Advertisements

16 Responses to Free wheeling in your car

  1. Autocar-Live says:

    I have submitted your article to http://www.autocar-live.com which is a social site about cars where users submit car/auto articles they like and vote for articles that others submitted and they like.

  2. George says:

    In the UK in the 1970s my father drove a standard transmission Saab 95 which had a freewheel like a bike. It coasted under momentum unless the accelerator was applied. Under the dashboard was a lever you could pull (when the car was stationary) to put the car into the more familiar “fixed wheel” mode, which was recommended on steep and twisty roads.

    This brilliant but simple idea made the car very economical to run. The only modification to driving behaviour was slightly more reliance on braking rather than the engine to slow down – an adaptation that anybody who had ever ridden a bicycle could make in minutes.

    At some point freewheel mode became illegal in the UK, on alleged safety grounds. Yet in our experience the car was safe to drive almost everywhere. It was only on mountain roads with hairpin bends that my father ever felt the need for “fixed wheel”.

    I have never believed the line that freewheel mode was inherently unsafe, and believe that the time is right to reappraise the idea. The environmental and economic benefits may well outweigh a small difference in safety, if it exists. If an optional freewheel mode were made standard in new cars worldwide the savings in greenhouse gases could be absolutely enormous.

    **Please forward this letter and let’s get optional bike-style freewheels in cars onto the political agenda.** Now that governments are finally dumping incandescent bulbs and banning plastic bags the time is right.

    George Lee Vancouver, Canada

  3. Charles Davey says:

    I am a believer in freewheeling. I drive a Toyota Sienna, and even with the third row of seats taken out it is still quite a weight. As there are a number of hills round where I live, I freewheel and it’s both safe (as long as the road is reasonably straight) and I believe – am I right? – that it saves me gas. The weight of the Sienna certainly takes me faster more quickly, unless I was pretty hard on the accelerator.

  4. greennav says:

    Hi Charles,

    I think it realy depends on the length of the freewheel. If your free wheeling for a long distance then there may be merit, but my research found that when you freewheel up to lights, and so breaking, it would have been better to let the engine slow the car, as it can use the momentum to keep the engine going, instead of petrol

    thanks for the comment

    P

  5. […] found this: Free wheeling in your car One of the comments claims that 1970's Saabs had a freewheel trans, until it was outlawed in the […]

  6. Автопортал…

    […]Free wheeling in your car « GreenNav’s Open Blog[…]…

  7. Service says:

    Service…

    […]Free wheeling in your car « GreenNav’s Open Blog[…]…

  8. Don says:

    did the old–1920’s and ’30’s have a FREE WHEELLING IN push/pull button on the dashboard?

  9. See web site: http://www.newtonvehicle.com
    Attention paid to patented safety brakes

  10. With this Sold Out After Crisis Assessment and commentary,
    you will study a set of guides that can get ready you for any catastrophe that might be headed our way, regardless of whether it is a hurricane, a flood,
    a terrorist attack, world war III, or an increasingly more likely financial collapse.

    Damien Campbell is often a survival professional who has spent ages learning survival topics for instance long-term food stuff storage,
    h2o purification approaches, choice sources of strength, unexpected emergency medication,
    and yard gardening. When he commenced scripting this guidebook, he begun by creating a record of
    foods to stock up on. The condition was that checklist was rather extensive, and
    a few in the foods ended up challenging to shop.

    While in the fascination of trying to keep his manual so
    simple as achievable, he narrowed the final right down to 37 vital foodstuff products that everybody order now ahead of it is much too late.

    Regrettably, the normal American has no plan how terrible issues
    truly are. The media would love to pretend every little thing is
    okay, but the truth is, we face much more risk now than we’ve got in decades. Farmers are functioning away from acreage, outdated sources of drinking drinking water are drying up, terrorists are more popular than ever, and deficit paying is draining our economy and could easily bring about hyperinflation.

    That is why it is so crucial to become geared up. For those who wait around until the crisis is at your step, it will be far too late for the reason that by then, the public will have emptied the outlets. A whole lot of individuals do not know this, but grocery shops only keep 3-4 times well worth of foodstuff on hand. And when disasters strike, that foods is absent in only 3-4 hours! It is occurred often times previously.

  11. Natural remedies are deemed highly efficient, cost effective, and significantly safe to use.

    Implementing these changes in your life, will be effective remedies against
    recurrent yeast infections, when undertaken with a holistic yeast infection treatment program
    that will kill the yeast infection from the inside out.
    Although the treatment has been successful for many
    people with Candida, be warned that some of the side effects may include excessive vaginal discharge, discomfort and burning in the vaginal area.

  12. Main Keyword says:

    Neat blog! Is your theme custom made or did you download it from somewhere?
    A theme like yours with a few simple tweeks would really make my blog jump out.
    Please let me know where you got your design.
    With thanks

  13. Hello, i believe that i saw you visited my weblog so i came to return
    the prefer?.I’m attempting to in finding issues to enhance my web site!I assume its ok to make use of some of your ideas!!

  14. In this diet system, the dieter is asked a set of 70 queries, the
    answers to which will establish the food habits, attitudes and physical
    exercise habits of the individual.

  15. Greetings! I know this is somewhat off topic but I was
    wondering if you knew where I could find a captcha plugin for my comment form?
    I’m using the same blog platform as yours and I’m having difficulty finding one?
    Thanks a lot!

  16. It’s an remarkable post in support of all the internet users;
    they will obtain advantage from it I am
    sure.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: