Significant increase in mpg by trailing other cars?
(2011-04-10 14:25:20) 1. Says: I recall a Mythbuster's segment about following close behind a large truck and significantly improving the trailing car's miles per gallon due to the decrease in drag. So I was wondering if it's actually cost effective to trail (safely) behind other large automobiles on the highway like maybe 4-5 car lengths and how much of an increase you can expect if anyone has the numbers. Does the decrease in drag also reduce the strain on your car so you're less likely to wear down the components? I feel I don't have to press on the pedal as hard when I'm trailing vs leading on the highway.2. Says: I've drafted off big trucks in a Jeep Cherokee with a 28 foot ladder on the roof before and gained 3-4mpg at fill up time before, so yes it makes a difference.In response to the other guy, they tried it at varied distances away, and the best result was at approximately 15 feet away from the truck if I recall, where they saw something like a 43% increase, which is not a small amount. When they got 5 feet from the truck, the increase actually dropped. If I remember, they gained about 15% in economy at a safe distance of around 50 feet.
According to a site I found, their results were this:
55mph control: 32mpg
100ft: 35.5mpg, 11% improvement
50ft: 38.5mpg, 20%
20ft: 40.5mpg, 27%
10ft: 44.5mpg, 39%
2ft: 41mpg, 29%
I was a bit off.3. Says: Well, is it worth endangering your life and mine for a few MPG? You'd have to be a complete IDIOT to consider this. Tailgating the the #1 cause of rear end accidents. You CAN however increase your gas mileage by 50% if you slow down. Try going 55-60mph. Synthetic in your car's oil and transmission where applicable. Pupm up your tires. Im getting 40MPG in a car rated for 28 hiway doing these things WITHOUT tailgating.4. Says: If I remember correctly, that segment showed the difference was NOT significant and you had to be within less than a car length, in other words, in an extremely unsafe position.5. Says: You will find the big gain from following someone comes from driving slower and letting off the gas more often and you don't have to follow to close..6. Says: Short answer is yes, you will increase your MPGs. By trailing other vehicles close enough to get a good 'draft' you are also increasing your chances of getting a ticket for following too closely, rear-ending the car infront of you due to decreased reaction distance, and increasing the damage done to your car by rocks and debris getting kicked up into your car from the vehicle you are following.
The increased hazards due to following a vehicle close enough to gain a few MPGs outweigh the money you can save on gas.
To the guy who said 50ft is a safe distance...it is not...unless you are going less than 20MPH.7. Says: I tried that once a few years back on an isolated road. I did this with my car at 2-3 feet from the rear of the truck for approx. 20 miles.
PROBLEM
Although your gas mileage may benefit there are a few drawbacks. I never checked my fuel mileage but i did come across the following;
- anything the truck throws up off the road goes straight into YOUR windshield
- there is no warning when the truck slows
- the dead air space at the trucks rear end plays merry hell with your cooling system. If your car utilizes electric fans they will come on.
- forward visibility is non existent
- without all that air rushing over your car you can hear every mechanical noise that your car makes and you WILL be convinced that your car is coming apart.
- Oh; and as a small aside. Don't stop where the trucker stops. He will teach you a whole new language if you do. They tend to get a wee bit testy with people who play games with them on the road. JUST A HEADS UP ! !8. Says: 4-5 car lengths is not nearly far enough to be safe. If a cop sees you driving that close at highway speeds they may pull you over. If you go by the "three second rule" (always staying three seconds behind the car in front) it allows for varying speed. At 60 MPH you would go 264 feet in three seconds, which is a lot more than five car lengths and way too far away to gain anything from drafting. 5 car lengths is less than half that on most cars, so way too small to be safe.
The bottom line is sure you could increase MPG by drafting big trucks, but the distances required for any real benefit would be far too small for safety and legal reasons, so it isn't realistic. Tag: Significant increase in mpg by trailing other cars?