Formula One cars and 'stock' cars are two different beasts. Stock cars (were) are the original shape of the car you can buy on the showroom floor, and are very closely related to bricks in terms of aerodynamics. Drafting works because of the relatively flat rear ends and front ends on stock cars.
F1 cars don't have this 'disability', they are meant to run in the open air to generate downforce to keep the car stuck to the track. Drafting doesn't work because the 'dirty' air behind another car disrupts the airflow and causes the car to become loose, handle poorly and not allow it to achieve top speed in a given situation.
What he doesn't mention is that the average speed on LA highways is about five miles an hour because of the congestion. This reduces the number of deaths due to collisions but increases the number of deaths due to shootings by frustrated drivers who have spent an hour moving a few feet and only need to get off at the next exit.
Out of some cruel sense of irony, the traffic is usually completely stopped during what they call "rush" hour.
Once upon a time, local councils in the UK could make their own planning decisions to avoid over-exploitation of 'brown field' sites.
Today, a local council is virtually toothless in the face of government regulations. Hence we have over-development of the above without any new roads and absurd traffic jams which the 'politically correct' assert would be fixed by using public transport. Except public transport on the roads is slow, uncomfortable and doesn't often reach you destination without multiple changes that don't wait for each other. Trains can be good on commuter services but even there, the overcrowding is insanely absurd at peak times. A recent local newspaper story told of a passenger who was fined for STANDING in the first class compartment because she had nowhere else to go.
You need to be well within a car length for the idea to work at all, and the effect is miniscule under about a hundred mph with today's reasonably streamlined cars.
I am convinced you waste more gas because of increased use of brakes because of control system transport lag than you could ever gain.
I purposely leave MORE than the recommended following distance so that I very seldom ever have to touch the brake on the highway, nor even make much throttle movement. Steady speed and throttle are the keys to good milage.
Agree with your comments. Some of my old racing buddies used to ferry cars for Herz, and they claimed they could save a lot of their gasoline allowance by "drafting" at speeds 100 mph or higher, and nose to tail.
Maybe true, maybe not, they tended to be FOS when they could get away with it;>)
I also try to leave a lot of room, which is hard in Houston freeway driving.
On the highway I find that smooth even driving gets me the best mileage....minimal acceleration or deceleration, minimum braking, mininum possible idle time.
I agree in general, but based on my experiences playing with my new Impala, that car at least responds best to brisk acceleration followed by coasting or just enough throttle to maintain speed. Also idling doesn't seem to burn as much fuel as you'd expect; you can burn a lot more by unnecessarily slowing down and then getting back up to speed. Being stuck behind someone accelerating slowly destroys your economy numbers - it doesn't like gradual acceleration at all.
They most certainly will. It just takes a lot more effort to operate them...brakes at least. The effort on the steering becomes a bit easier as speed goes up but it is still "stiff".
Esp for the retun in gas mileage you'll get.When I was young and indestructible I used to do it, approx 3-5 feet off the back of an
18-wheeler at 60 MPH. Yeah, for that trip I got about 3 more miles per gallon. But you have to PAY ATTENTION and be fearless to do it!
The other thing is, the price of gas then was $0.75 a gallon. The price of diesel was $0.32 a gallon. Some truckers didn't mind if you coasted on them. They weren't paying the gas, and I guess they figured if you wanted to kill yourself to save a few cents, so be it.
The independents that pay their own gas don't like it at all. There was one guy that didn't 'brake test' me, but when he passed another car he'd cut back in quickly so I didn't have a chance to get behind him. You gotta remember: what you're saving, they're losing.
There was one guy that knew I was back there and did everything he could to let me know what was going on: early turn signals, early brake lights, plenty of room to pass, etc. I followed him from Florida to North Carolina where he had to pull into a weigh station, and as I passed he smiled, waved and gave me a blast on the horn. Those are very few these days.
I also got 37MPG in a fully loaded Toyota Corona for that section of the trip!
It kind of works for motorcycles too if you're wet and cold and just using the truck's exhaust for warmth and remember to pull out before you pass out.
The apparent effect of idling (on board mileage indication) is rather severe in my car. It is difficult to measure this accurately by actual gasoline consumption versus actual mileage figures.
My car, however, DOES accelerate briskly when on cruise control, and this doesnt seem to effect mileage negatively.
I easily average 32 mpg on the road (2007 Avalon, 286 hp V6). And this figure correlates well with measured values
You have to decide between freezing and asphyxiation, but it seemed to work fine. Perhaps some technical person can explain eddy currents or wakes or cavitation or something...
I call it 'Zen driving'. Go with the flow, don't leave a wake, or cause ripples from people having to move around you. Traffic is like a fluid, and principles of fluidics apply. Sir Jackie Stewart, the racing driver, addressed the concept at length, calling it 'smooth driving'. And he drove back when the hardware for each team wasn't within a fraction of a percent of each other on capabilities- if your car wasn't the best, your driver had to be. First heard him describe it 20 years or so ago, and it made so much sense I've tried to follow it since then, as best as my skills and traffic conditions allow. It also draws the least amount of attention from the cops, which helps at times.
It IS true that very light throttle for acceleration is NOT economical. When you accelerate, max efficiency comes at around two-thirds throttle, just before power enrichening kicks in (this is with a throttled engine, not so true for a Diesel). However, you need to keep rpm down by shifting early. This can be a problem with automatic- use as much throttle as possible without raising rpm of shift points.
But most cars don't coast that well. You need to take it out of gear and turn engine off to really get milage that way. Full throttle and coasting is how those super high milage cars in contests work. In that case the throttle is removed from engine. But those cars have solid tires, or very high tire pressure, and super low friction axle system. You also need to keep speed down to avoid air drag. Coming up with the optimum profile (speed to terminate acceleration, speed to resume) is a very hard job to determine.
I can remember being taught when I learned to drive to avoid short shifting- lugging was bad for engine. However, that was a half century ago. I remember reading a test report by a European mfgr in the seventies that said short shifting was okay now. New crank and bearing materials, and more importantly, better lubricants, had eliminated excessive crank wear, as long as shuddering did not occur. FI seems to have eliminated shuddering, at least on port injected engines.
Coasting in a late model GM, at least the ones I've driven, is pretty economical - they seem to use real loose torque converters and they unlock as soon as you come completely off the throttle, resulting in an almost complete lack of engine braking. This was a real problem in my '05 as it resulted in having to ride the brakes on any kind of downgrade (or else downshifting, not sure how well those transaxles take to constant manual downshifting though.) Went through two sets of brakes on that car in 80K miles which is WAY more than I've done in any other vehicle. The '08 seems to be somewhat improved in this respect - it stil works the same way but does have a little more engine braking; maybe GM got some complaints?
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