Thread: drafting semi's
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Old 12-18-2011, 10:53 PM   #30 (permalink)
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The buffeting you will feel is the vortexes off the sides of the truck. Moving closer will get you out of the vortexes and it depends on the size of your car. You can also see it when it is raining if you use rain-x on your windshield. The drops will normally run almost vertically off your windshield in clean air (no draft). When you get in the draft they go crazy weaving and even going in circles sometimes.

I don't like getting real close, with 100 feet about my minimum. The stripes on US roads are right at 43 feet from beginning to beginning of each individual stripe. When you barely have 3 between you then you are right at 100 feet. Get right at 4 visible and you are at close to 140. Look for trucks with large mud flaps and especially those with the rear section closed at the rear down to about 2 feet off the road.

Best drivers I have seen here are Wal-Mart. Very consistent as a norm with UPS drivers close. Many will actually slowly lose speed climbing a grade and go to a higher speed downhill. This was the type of trucker I found on my summer of 08 trip of 300 miles in my old VX (sold) that got me 68 MPG for 300 miles, even including 2 hours of night driving coming back home. On one stretch there were at least a dozen trucks drafting each other, and I just followed the pack. Other trucks would pass me a pull over in front of me to pick up the group draft, and I let them in, since they were saving a lot more in fuel than myself. Nighttime was much more stressful, constantly keeping a vigil for the inevitable large piece of truck tire in the road, but I never had to swerve off the road.

I'll bet my Maxima would do 40 MPG under the same circumstances, but in mid 2008 the truckers were running 64 MPH average. They have since raised the speed limit to 70MPH on the same stretch of I95 south from DC to Richmond.

regards
Mech
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