Fuel To Weight to Drag Ratio

1313

OK I have got a old but reliable turbo diesel, so already fairly economical.

Nearside wing mirror missing........is my car even more economical?

Driving with the windows open uses fuel....how much??

Boot is empty........is this good?

I never wash the car, saveing money?.....or more drag???

Lights on how much fuel used?

OK what I am asking is, does carrying extra weight expend a lot of fuel? If I stop carrying the fuel can in the boot, rip out the carpets, remove trim, etc. etc. do I save much?

1313

Mmmm not much of a response to this subject.........should I get a life???

Naah!!!

I have for the past few weeks been driving my old heap with over inflated tyres. The result is that I am getting an extra 60-70 mile per tank. OK so I am waring my tyres out possibly quicker, but I am saving over £5 on fuel. Can't think I am waring the tyres out at a faster pace than that.

Driving is certainly a bit harder, but it is more responsive.

tonys_3

Sorry 1313 I missed your original post.
Most of the questions posed in June very hard to put any kind of figure on them.Partly because the savings achieved woild be so small that it would be impossible to check them with any degree of certainty.The
savings involved in not carrying a spare fuel can would be minimal especially if you are
getting 40 odd to the gallon anyway.

Of far more concern is what you say about your tyres.If you are driving with your tyres
more than 20% over inflated ie about 6psi,then not only is that illegal,but your
insurance company could use that to refuse any claim you make if you have an accident.

If you want to save on fuel,drive more carefully[not that I am suggesting that you don't now] and more slowly.Find out what the most economical cruising speed is best for your car and try to keep it there as long as you can.Remember blipping the
accelerator a couple of times at the traffic lights for instance would more than wipe out savings on ripping out your carpets for some considerable time.

Porker

Lightening a car improves many features – performance, handling, and braking – but in order to achieve this you need to be removing lb’s not just not having a wing mirror. Track specials, such as the Porsche 911 GT3 RS have no carpets etc and plastic windows, as well as having a Porsche crest sticker on the bonnet, instead of the normal enamelled badge. All these things are done to reduce weight, in order to squeeze every last benefit from the car.
Taking carpets out isn’t really going to achieve a lot as the weight is low, replacing the glass with Perspex would drop a lot of weight, but is dear to do. Changing your bonnet for a carbon fibre one would drop a lot of weight too, but again is v dear. Personally, to get the most out of your car I’d not carry a load of crap in the boot, don’t carry spare fuel, and having the windows up will help (but only a tiny bit!). Going on diet would have more effect.

I’m pretty sure that worrying about how much extra fuel you use when you have your lights on is unhealthy.

Also I’d echo the earlier sentiments about your tyres – rubber is cheaper than metal, so don’t skimp on tyre safety, if they are over inflated you have less footprint on the road and your levels of grip are reduced significantly – you’re not saving money if you skid into the back of someone.
The best things you could do for the car is to keep it in good working order, properly serviced etc and it’ll run as it should, i.e. efficiently. Try an injector cleaner every now and then (Wurth do a good one), and probably give it an ‘Italian tune up’ every now and then to blow carbon residue out of it, particularly if you’re pootling around all the time.

misterthrifty

And ride a bike instead whenever you can, saves loads of fuel!

Mr T

aardvark0

I agree with Porker 100%.

My car manual (Peugeot 205) states that having the windows open affects fuel consumption negatively by about 5% - apparently if the choice is between using the air blower and the opening the windows you should go for the blower. Obviously on a hot day most people would be prepared to take the fuel hit!

One of the easiest ways to lower fuel consumption may be to clear the car out; lots of people cart an awful lot of kit/junk around which is probably not necessary, and of course this burns up fuel. I would draw the line at pulling the carpets etc out though.

As for overinflating the tyres, ignoring any legal issues, the fuel saving comes from having less tyre contact with the road. This is more likely to casues wheelspin when accelerating strongly, and will massively detract from your braking power when you really need it. Obviously this impacts on overall safety, but also causes additional wear and tear on the centre lines of the tyre causing you to need to replace them more often.

Reaper

I guess a full fuel tank must make some difference as it must weigh as much as another person in the car.

I know putting on air con increases fuel consumption but I think lights will be too minor a difference to bother with, and the other points you mention are either too small a saving or too dangerous to consider.

A badly packed roof rack can make a big difference. Don't put a large flat surface at the front.

A common view is that driving at a steady speed is fuel efficient. However I have heard that an accelerating engine is more efficient - I don't know if that applies to diesels too.

The theory is that is you should, say, slowly increase your speed from 30mph to 70mph, then push out the clutch and coast until you drop to 30mph again. I have not heard of a scientific experiment done but did read an anecodotal report that it saved around 25% fuel.

I suggest you only try this on an empty motorway at night or you could seriously annoy other drivers!!

1313

Over inflating my tyres gave me an extra 75 miles from a full tank of fuel!! However, the car was more skittish on cornering, I blew three bulbs (possibly due to more vibration), and the ride was not nice. So I suppose all that I can do is empty the boot of rubbish.

Does anyone have any experience with those gadgets that attach to the fuel inlet pipe, do they make a difference??

Silent_Bob_3

1313 wrote:

Does anyone have any experience with those gadgets that attach to the fuel inlet pipe, do they make a difference??

They're a waste of money as they dont work. If they did all new cars would be fitted with them.