I commute on a weekly basis from Las Vegas to Ridgecrest, CA (235 mi) and decided to run a little "drafting" test tonight. I typically set the cruise at 65 and achieve about 49 mpg per trip. Tonight I got behind a 18 wheeler running 70-75 and followed him for about 175 miles or so on I-15. I was inside his wind vortex following at about 25 ft or closer (not recommended but mildly amusing). My MFD average went from 44.5 MPG outside of Bartsow (at 65 mph), to 63.5 MPG (at 70-75) by the time we got to Tropicana - and it's an uphill run. I couldn't believe how many 5 minute segments of 99.9 MPG I saw. The battery was 10 bars full green the majority of the way and the motor was generating instead of producing for minutes on end. Several times (at speeds up to 72 mph) the car went into "super-golfcart" mode where the electric motor was providing the sole source of power. I imagine you could achieve better than 75 mpg traveling cross-country using this technique. I think I'll get at least 650 miles out of this tank, but I don't recommend following that close... just wanted to see what would happen. Also, a fella in a maroon '05 Prius tagged along in the train for the last 30 miles or so... the first Prius I've seen in a long time.
Re: "Drafting" experiment... 50 mpg to 65 mpg, eas At one point several years ago, I was thinking about getting a Honda Insight. The newsgroup I monitored discussed several techniques like that. They also noticed mpg improvements by positioning themselves on the crest of the air flow disturbance. I think the guy who wrote about it referred to it as surfing.
It works. I stay back about one second and get results of around 52 MPG at 77 mph. BTW get ready to be scolded by others. Scolding yourself first won't help.
I used to do this all the time when on 101. The only drawback is that if the highway isn't clean, you be getting little rock chips in the very front part of your car and not know it. You can hear little pebbles when they hit the hood, b ut not the lower front area. my car is pretty chipped up
great results!!... try drafting in a F-150... you will double your mileage. and in isolated areas, drafting behind a professional driver is not as dangerous or difficult as driving with idiots under any circumstances imho.
1 second at 77mph!! Not with my family in the car...that's what, 112 ft. following distance, your reaction time is practically 'nil'. And if it's a semi or large enough SUV to get a decent draft off of there's no way you can see around it to help anticipate problems. Just last week I took care of a 19y/o who drove his car under the back end of a semi. His friend in the car died and they were still trying to extracate the body 4 hours after the accident. The patient I took care of took over 30 minutes to extricate. His face was fractured in too many places to count and he had serious brain damage.....he was wearing a seat belt and had an air bag. My understanding is that a 2 second following distance is adequate to benefit from a draft, and I use that sometimes, but please folks consider risks and benefits and driving conditions before ever trying this. A few pennies saved is just not worth the risks....and they are very very real risks.
Evan: I suppose the neat thing about your line of work is that on an almost daily basis you get to see Darwinism in action. Jay
The best way to do this is to mount a HV battery-powered electromagnet to the front bumper or your Prius. On the highway, creep up behind a large truck until your front bumper is almost touching the rear bumper of the truck, then engage the electromagnet.
I have tried drafting on a few occassions. My adult ADD doesn't allow me to stare at the back of semis for very long. Booooooorrrrrrriiinnngggg
well i dont recommend drafting to anyone... but i realize that a truck will not be able to stop faster i do so that a following distance of one second will be good enough. obviously i will be paying extra attention to what the truck is doing and i dont do it when others are in the car not so much out of concern for their well-being. its more like, i dont want to listen to them b**ing about my driving.
Re: "Drafting" experiment... 50 mpg to 65 mpg, eas I draft as much as I can about 1.5 car lengths behind any car. One thing to remember, EVEN IF the truck/car in front of you can't stop any faster than you IT STILL CAN if it HITS something. So, I try keep an eye on the car in front of the car I'm following (if I can, damn trucks and tinted windows) in order to get more reaction time. So, something I learned driving up and down the insane section of the 5 near the 710 where all the slow traffic is on the LEFT. Back to your regularly scheduled programming.
With a small car like my MR2, I really like to draft someone else and not have to touch the gas pedal much or worry about winds blowing me around (happens a lot in the MR2). But there are a couple of caveats when I do it with the MR2: 1) I can basically draft anyone due to the size of the car (last night I drafted a new Mustang on my way up here to Charlotte), and 2) I can really feel when I'm out of the draft because the wind blows my car so hard it takes some effort to keep it in place. Being behind a semi is touchy, but this is what I usually do if I'm going to draft one - Only draft a semi that is going the relatively same speed all the time and is driving the same speed as I'm used to. This helps in reacting to his driving and also puts me in a zone to where I know how my car will react in certain situations at that speed. Let the semi know you're behind him. I normally only draft trucks that I'm letting over into my lane in front of me to pass someone else. A simple flash of the lights lets him know I'm there and that I'm staying behind him in case I fall into a blind spot.
Typical reaction times are 1/2 second. My usual following distance is 2 seconds. At that distance people will regularly cut in and reduce mine and theirs to less than 1 second in less predictable traffic patterns than driving the interstate behind a tractor trailer rig. The stopping distance for one of those big rigs is twice that of the Prius. If the truck hit something, it would probably not reduce it's stopping distance as it would drive the other vehicle and would likely lose control of it's own braking system. In any event, the scary story you told has little to do with this, other than involving an 18 wheel truck. Can you share any details of the causes of the accident. Unfortunately, 19 year olds use judgement that is beyond our capacity to explain. I can't explain the things I did at that age. If what I was doing was dangerous, then driving in rush hour traffic should never be done. I think it may sound worse than it is.
The reality is that it is actually more dangerous than it seems. But you're right about the cutting in and the dangers of rush hour driving. It's a risky venture and there are a lot of accidents. Many are bad, many are almost terrible. We all run risks and I'm not 'scolding' anyone. I'm pretty much a live and let live (or die) kinda guy. But 1 second at 77mph is too close for safety and the risks are high, if not frequent....the bad things don't happen often, but when they happen they're very very bad.
I try to avoid drafting behind any trucks that have sub-par mud flaps, if I draft at all. It seems that most of the trucks in this area do not drive consistent speeds (or drive too fast), so drafting tends to be unproductive in many cases.
i have to agree with Ray. in my area during rush hour traffic, nearly every day i will see a line of 3-5 cars or more all bumper to bumper in the fast lane travelling 65 mph (reason is obvious... they all want to go faster than 65 except for the guy at the head of the line) average following distance can be as little as 20 feet. in that scenario, being able to see around the cars in front of you is not enough. your foot wouldnt even have touched the brake by the time you hit the car in front of you. i will say that in my experience, many truckers if they are in a position where they dont think drafting is safe, they will let you know. if that happens, back off. but i have seen truckers drafting each other. the one benefit of drafting is that even the frontman gets better mileage too because the following truck will eliminate the rear end downdraft and turbulence so can benefit from it.
Yeah, around here following too close to a semi is the best way to get a rock in the windshield. I try to keep at least 5 secs behind a large truck. I usually stay in the slow lane of a divided highway, and if some a**hole wants to pass, let him pass. I've never been a Speedy Gonzales and sure won't start at my age. If some a** still tries to tailgate me, I just use the cruise lever to gradually decrease my speed in 1 km/h increments until he gets the idea and passes. Idiots. They're the ones that cause accidents too.
or tap the brakes to get the light on. Then he'll get annoyed cause he can't tell if you're braking hard or not and will overtake, usually with the one finger salutation.
