The Tornado definitely does not improve fuel efficency. The theory behind the tornado is that air moving in a spiral flows more efficiently than air moving directly and therefore you can get more air into your engine, which will make it more fuel efficient. The problem with this theory (if it even holds up) is that you install the Tornado in your main intake tube, between the air filter and the intake manifold on the engine, where the intake divides to each cylinder. So, even if the air is moving more efficiently before it hits the manifold, that will not hold up all the way into the engine. For another reason to not install the Tornado, consider what will happen when one of those flimsy fins on the thing breaks off and flies into your manifold.

None that I have ever seen. Most of the claims made for these so-called fuel-savings devices are anecdotal and have not been validated by third-party investigations. However, there are several reliable ways to control your fuel consumption: - Purchase a vehicle with better-than-average fuel consumption and keep it in good mechanical condition. - Adjust your driving habits to economize on fuel consumption (e.g., drive under 60m/h or 100km/h, no hard acceleration). - Limit the distance you drive by leaving the car at home when not absolutely required (drivers in the US average more miles per year than any other industrialized nation). - Combine several errands into one trip and plan your driving route to reduce the distance travelled. - Don’t leave your car idling for any longer than necessary. If you are going to be parked for more than 30s, turn it off. - Modern cars do not need an extended warm-up period in cold weather; 30s to 60s is usually adequate. Remember, all cars go the same distance per unit of fuel when stopped in traffic: nowhere/gallon or litre. There's one thing most people overlook: if a simple widget that cost $10 to produce could improve gas mileage by any significant amount, would not auto manufacturers use such devices to improve their corporate average fuel economy to meet government regulations, rather than developing costly and complex solutions? If such a widget worked, it would be the easiest and most profitable way for auto companies to meet increasingly-stringent regulatory demands.

Keep your tires/tyres at the recomended pressure and check them regulary, those little black doughnuts WILL eat lotsa gas once they get low on pressure!

Yes. It's called a gas pedal. Use it wisely and your fuel will go a long way.

What about the "Tornado" that you put in the air cleaner ?

Well speed limiters - but you can do that yourself by not pressing so heavily on the gas pedal. I think the best thing would be a foldaway bicycle in the back. Especially if you can park out of town and then cycle in.... Of course you need to take into account the extra consumption due to the extra weight of the bicycle, but cycling will probably reduce some of your own weight!. The rest have been said by others - ensuring the tyre pressures are right. I have seen the adverts for the add-ons to fuel to improve consumption but if they were half as good as they claim - Im sure everyone would be using them. They never seem to get the backing of the RAC or AA or even the newspapers.

most don't. there are some chip sets or intakes that can help, but i think the expense for them outweigh the savings in fuel unless you drive a lot. the best things to increase fuel economy are the easy/cheap ones like correct tire pressure, going easy on the throttle, change oil and air filters regularly, keep plugs and wires changed regularly, et cetera...

no most engines today convert 99% of the fuel to energy. tha doesn't mean it is 99% efficent, a good deal is made in the form of heat, but the engines use almost all of the fuel. The best way to improve mpg is to slow down. going from 80 mph to 65 on the hwy will gain some cars 8mpg. and take a open cup filled with water 1/2inch from the top,put it between your legs, now pretend this is HOT coffee, now when you accelerate and brake you should not spill any. Search consumer reports on fuel economy for more