Hi im lookin for some advice. Iv only had my 206 GTI hDI 110 for around a month now. At first i was very happy with the fuel economy! The last few days whilst driving all of a sudden the fuel consumption drops to between 38-42mpg. (yes on instant MPG) when this happens the average MPG drops down and so does the miles left to empty! I drove home on saturday a 40mile journey with my girlfriend with me and drove very gentle i.e no hard aceleration or anything and sitting at 60mph and only avreaged 42mpg. I could average that journey 40mpg in a fiesta ST!!!!! I was getting high 50s to start of with.

I got this car to save money on fuel, So please help me out!

Any help will be apreciated thanks

{subject header made less vague, and some SHOUTING here and there amended} Read more

OK most people has GPS with tax camera locations on now but if all you need is the cameras and you can read a map then this has to be unbeatable.

Offer available on their website. Read more

Whilst the media is filled with people claiming that a hybrid is the way forwards (America) or that a small car with no luxuries is the only possible way (various pressure groups), it amazes me as an engineer that very little effort is put into exposing just how much more we can get without going very far off the beaten track and certainly without adding huge complex systems of hybridisation to a vehicle.

Certainly a primary concern is going to be saving weight, and we can do that very easily by using Aluminium albeit at a cost compared to using Steels. This is of course consequence that few people are willing to pay for in comparison, because ultimately the bottom line matters to anyone, however a premium of £1000-1500 for car can be shown to work when the return is great enough e.g. diesel engines currently command this kind of premium in many cases.

What I'm more interested in though is the ways in which the engine itself can be made more efficient. The first one is really simple, downsizing and turbocharging to capture waste energy from the exhaust and we're seeing this happen at the moment, but we could happily take it further than this. The heat coming out of the exhaust isn't all consumed going through the turbo (though it would be nice if it were - turbines/turbos work using a delta in temperature across them to harness power). That low grade heat that is left is of a similar value to that discharged by the cooling system, not really hot enough to do useful work but of significant cost anyway. BMW made a demonstrator a couple of years back that captured exhaust heat to add extra power, and there's no reason why we couldn't do this to generate electricity or even run the air conditioning system. This works more or less the same as a kerosene fridge and would remove significant loads from the engine e.g. a Range Rover has a 14kW (19Hp) air conditioning pump and a 100A (say 5Hp) alternator. Now imagine how much less fuel said car would use when not consuming a "base load" of 24Hp before even moving. We should start on the bigger cars too because there is more potential benefit here.

We can do much with gearing too if the motoring press and motorist can get over the idea that they would have to shift down or the transmission would have to shift down to accelerate. This is akin to keeping the revs low and throttle open (most efficient running is generally at 3/4 throttle or so with lowest engine revs that generate the necessary power) whilst cruising.

A good example of what can be achieved in miniature in a car is what we see in CHP power stations. The company I work for, a well know UK aero engine manufacture has installed gas turbines in power stations in Europe where the combined output efficiency is over 94% considering the electrical output and the heating output used in the local area. We already use the heat from the engine to warm our cabins, we could also use it to cool them too.

None of these engine based technologies are new, nor substantially heavier than those being removed (aircon) and nor are they unproven. What they are though is a shift from the norm, and the question is which manufacturers are willing to make the first jump. Personally I hope it's Tata Jaguar/Land Rover because they have the most to gain and the best models to demonstrate on due to their current consumption rates. I suspect it will be BMW however and to be fair to them their efficient dynamics packages should be present on all cars as a licensed technology or manufacturers own derivative.

What ideas do other members have for improving our cars for efficiency? Read more

Dear all,

I have been offered bio diesel (specifically manufactured) to european standard EN14214, for use in my alfa GT.

The company that remapped the ECU specialize in racing diesel cars and they have said there should be no probs.

What do people think about this considering its almost brand new, i intend to renew the fuel filter after using biodiesel for the first time.

The fuel cost 96 pence a litre and will be delivered to my home for free!

Is this too good to be true?

Kush Read more

Ok, the next issue on my uncle's camper van is that it now occasionally jumps out of 5th gear. We are aware that this is a common design fault following a re-design of the gearbox. My uncle has rejected my suggestion of using an elastic bungee on the gear lever when 5th is engaged.
I won't touch gearboxes these days without a manual. We have a good local gearbox specialist. Does it make more sense to fit a recon box or ask the local specialist to repair the box?
Camper vans do my head in. They are built onto cheap chassis that are designed to run up 150,000 miles in 3 years commercially, then be sold for peanuts at auction. However, the campervan fraternity expect them to cope with tiny miles over many years and are then surprised that they deteriorate faster than cars. Read more