| Soundy | 03-10-2011 10:18 AM |
Quote:
Originally Posted by Berzerker
(Post 7336719)
Theoretically you get longer fuel economy and long brake life while running with lighter weight ie. less fuel. I'm not sure the weight of fuel compared with say water but if you have a 60L tank (1L = 1kg, 2.2lbs) that means your 60L tank weighs 60kg or 132lbs. Now if you run at half tank or lower your running around with 30kg or 66lbs. It's the equivalent of driving around with a small child in your car. Hardly the dramatic difference in weight you would expect. Obviously the bigger your tank is the more it's going to weigh and the smaller your car is the more the weight difference is going to mean. If you were only running 10L and under a day and your tank size was 60L that would be 50kg saved or 110lbs. I personally know that driving around in a small displacement car you can very much feel when you have a passenger in the car when going up hills. Likewise can be said for a full fuel load. This also has an affect on brake life with reduced momentum when stopping.
Berz out.
| Good theory... in a vacuum. But what is your time worth? Is it worth the extra time to make those repeated stops for the few cents' worth of fuel you'll save? If your debit/credit card has any sort of per-transaction charges, that will increase the "actual" cost. And there's the theory that you shouldn't run your gas tank too low or you stand a greater risk of sucking up sediment from the bottom of the tank (I don't buy this argument, but if you're going to buy into the less-weight theory, this one might be your cup of tea too).
Consider that 100lb saving on a 2500-3000lb car is a tiny percentage and will have an even more minuscule effect on fuel economy... you can't compare to F1 cars that weigh less than half that (typically 1,000 to 1500 lbs, *including* driver and fuel). Besides, if weight was that big an issue for F1, they wouldn't have aerodynamics that add downforce of up to two times the car's weight. | 