How much do you save by driving with the windows open?

patman99

Used to own an Espace (1997 2.2TDCi model). Handbook stated that at 56mph, the mpg dropped by 12.5% with all windows half way down.
Every vehicle will be different. After all, they are all different shapes and sizes.

ariba10

You will have a lot less drag if you took out the front and rear windscreens.

Wig

Can't watch the video.... what is the conclusion of the test?

System

One thing to take into account as well is how far can you get before the first sprog pukes and you are forced to have all windows open to clear the smell to prevent the other sprogs puking?

alastairq

hi...get those windows open!

On most of today's roads [other than motorways]...constant cruising speeds are pretty much non-existent, due to the presence of other traffic all doing its own thing.

BTW, my Felicia estate [made under the auspices of VW...and using many of their bodyparts, so rusting may well affect things like the great-and-glorious, oh-mighty-one..Golf....?]..........according to the driver's handybook, uses 30 psi's in all tyres.

Now that rain has officially been banned by the Con-dem govt...I add a couple of psi's to those figures [NB.....if doing that, keep the ratio of tyre pressure front-to-rear the same]......lessens rolling resistance....and makes the steering lighter if no PAS is fitted [or working?]...



In warm weather [[ie no frost present]...I open the passenger side window for fresh air....[if on my own]....rather than the driver's side.....stops the wind blowing my hair all over the place!

Keep the sunroof shut.....stops it leaking eventually...
If it's an MPi, try coming off the gas [onto over-run] as far away from your intended slowing point as possible.....let the speed fall off gradually.......on the over-run, all fuel is returned to the tank......


Make full use of downhill bits...again on over-run..[rather than driving on a light throttle]...

On this car.....at tickover revs, fuel is fed into the engine.....you will know if you are at a too low rev point in a gear, as the car tries to surge forwards a little bit......when that happens, time to change down to the next gear.

In my 'umble view, the most missed departure from automotive styling is the opening quarterlight window.

StaffsSW

If you put into practice every "fuel saving technique" mentioned it is actually possible to save 116% of your petrol bill...

In all honesty though, I was filling up one of my cars, neither of which are what you would call frugal, and the guy at the pump next to me in a diesel Pug estate was whinging about prices, fuel economy and all the usual stuff. But he had a pair of roof bars with nothing on them, one tyre was under-inflated, and in his boot was a trolley jack and large metal tool box.

For those that understand, no explanation is necessary, for those that don't understand it would not be possible to explain.

alastairq

all of which , when added together, equal the weight loss I suffered after my last dieting session?

Are you saying, to save fuel, lose more weight?

Lum

Roof racks cause a /lot/ of drag, this wastes much more fuel than a bit of extra weight.

alastairq

Lum wrote: »

Roof racks cause a /lot/ of drag, this wastes much more fuel than a bit of extra weight.

of course they do.....

but in the example quoted above, who is to say the driver hadn't just dropped off his ladders or whatever, prior to filling up?

I don't know many folk who...when using a roof rack regularly, have the time to repeatedly remove them and replace them?

Of course, if the roof rack comes out for that once-a -year visit, then the advice above is sound.

[were there not devices one could affix to the rack, like a deflector, to reduce drag?]

Lum

Well, nobody knows, but we've all seen plenty of situations where people really could have taken them off.

My favourite is those roof mounted deflector things that people fit to improve fuel economy when towing a caravan. They're basically a rotating sheet of plastic bolted to a roof rack and you point them at around 45 degrees.

For some reason, everyone who owns these things set them to 90 degrees (i.e. vertical) when they don't have their caravan attached. Sometimes you see them hurtling down the motorway at 90mph + with these bloody things stuck on top causing drag and wasting their fuel.

Not my money, so it doesn't really bother me too much, but if there's going to be a fuel shortage (I mean long term here, not due to the current strikes) then it's quite annoying.