Drafting - pros & cons

[Big Dave]

I get tempted to do it from time to time. If you can catch a truck doing over 70 they have an enormous effect. If I let myself get within 20 feet on him I can coast and literally have had to hit the brakes to stay that far back. And all this in a 7500 lb pickup.

That said, my old ticker cannot stand the prolonged stress of tailgating semis for any meaningful length of time. I have driven too much and seen the debris that trucks can kick back at you.

[max_frontal_area]

and make a friend on a long drive. get permission, coordinate, have the truck driver warn you of debris, conditions, the fuzz e.t.c.

moving trucks are best, fedex trains are a close second.
remember a loaded semi takes a football field to stop, plenty of time
for you to do your thing in a 4000# jalopy. avoid sucking up to trucks
emanating from our "southern" NAFTA partners (dont think it is legal to use the M word anymore is it?) as they shed more than just exhaust gasses.

regardless, snoop around as best as possible inspect wheels for out of round/balance and more often than not bent rims. sparks shooting, likely
from a steel belt wearing off and anything else that seems funky - go find another donor!

to do this, it takes the appropriate personality, sounds reactions and a bit more training and skill than what a class C drivers test requires . the risk factor still exists but can be minimized with communication.
fuel savings can be enormous especially @ acellerated speeds.

[user removed]

Best mileage I ever got in a non hybrid was 300 miles on 4.627 gallons of fuel. Summer of 2008 in my 94 VX. I64 west to Richmond, then I95 north to exit 152B to Chantilly. Gas was spiking at $4 a gallon and the big rigs were slowing down to 64 MPH in a 65 zone.

Right lane, 3 stripes behind, always the shoulder as an escape route. Same pump same station, same day. Rode home at night with the lights on, might have hit 70 MPG if it had been daylight. On the ride back there was once 12 big rigs in front of me in a train, trying THEIR best to get max mileage.

regards
Mech

[HighMPG]

I remember doing this in my first car 1988 Conquest Tsi Turbo on the way to Stockton, CA because of my old memories of watching nascar and their drafting fuel saving techniques!
Who said you had to be going slow to save fuel!
I have tons of Semi's pulling large trailers on HWY 880 so 70% of my daily trip I draft.

[Fat Charlie]

I've lost windshields to rocks before, but that was from the road being crowded, not drafting. If a rig is worth drafting then it'll give you a solid (even if not optimal) benefit at a safe distance. When I draft I'm no closer than usual, I'm just behind that guy on purpose. I can be spotted drafting only because I don't pass him, not because it looks like he's towing me.

last night going home I got passed by a charter bus just before the top of a small downhill. The way traffic and that downhill works I start down it at about 60, glide down about halfway and have to pulse again because I'm already down below 55 and this isn't a stretch of road to be screwing around on. Anyway, last night the bus passed me. I moved left and ran it up to 70 then headed downhill. I was still doing 70 at the bottom and had to brake for traffic, and I wasn't any closer or farther from him than I would have been with any other vehicle there.

[hmiwb]

I don't draft although I'm not knocking the practice. From riding on motorcycles quite a bit I've discovered that unless you are quite close to the vehicle in front there is a tremendous amount of buffeting that occurs as you drop back a reasonable distance behind the front vehicle. I can't imagine how that "dirty air" can give you very good aerodynamics although it seems to work for some. I prefer to be away from all traffic if possible so I can vary my speed a bit and drive my own pace.

[D.O.G.]

Originally Posted by Fat Charlie

When I draft I'm no closer than usual, I'm just behind that guy on purpose. I can be spotted drafting only because I don't pass him, not because it looks like he's towing me.

That's the way I approach drafting as well.
If there's a truck going the speed I want on the freeway (10kph under PSL) I'll happily tag along behind him.
However, I don't try it anywhere there are side streets, traffic lights, etc. I already have trouble seeing far enough ahead in traffic due to a low roof height.

[HighMPG]

I have seen semi's lock up their brakes and they don't stop very well.
Draft along fellas! lol

[UFO]

Originally Posted by HighMPG

I have seen semi's lock up their brakes and they don't stop very well.
Draft along fellas! lol

You are failing to account for your reaction time. If a truck brakes hard, you will hit them before you have a chance to get your foot on the brake. At 70mph and 50 feet behind, you have 0.5 seconds before you are in it's butt.

I amazed some of you even consider this, let alone practice it. I hope you get cited before you kill yourself.

[MetroMPG]

Originally Posted by HighMPG

I have seen semi's lock up their brakes and they don't stop very well.
Draft along fellas! lol

The biggest danger in following too closely isn't necessarily the stopping distance in front of you (assuming you're not napping at the wheel).

Following too closely makes you a reactive driver, instead of a driver that anticipates based on what is happening down the road. It's even more true if you're following a big vehicle that you can't see past.

When you're too close or can't see, you're more at risk of being run into by the driver behind you because you have to brake as hard and as fast as the vehicle in front.

I'd rather use a big safety cushion in front to absorb changes in speed more gradually, and give the tailgaiters behind more time to aviod smashing into me & each other.