I did not know how far the wake of a semi would be until my ac broke on my Mazda. I took my 94 Intrepid automatic. It has a scan gauge type real time mpg read out upto 100 mpg. I was very shocked at the distance from the truck that my mpg started to rise. As i slowly approached the mpg continued to rise. I thought i had to be very close to get any results. Now i know different. I could see how different type vehicles affect my mpg.
had a chance today to draft a semi while using a scangauge. driving my wife's car(my car is not SGII compatible)gave me this opportunity. VERY interesting.
70mph avg ~29mpg no drafting. when drafting(i'm a truck driver, so i did so w/ mirror in view) again @ 70mph avg ~35mpg.
now, this is where it gets interesting. drafting, same speed, downhill(slight decline--not very hilly here), yeilded a high of 182mpg. WOW!
When drafting you often get a sucking sensation where you are literally being pulled by the truck which is why a Prius' battery will get charged full up on a down hill when drafting and why you saw a high of 182mpg. I guess this primarily happens on downhills.
Drafting does not slow the person in front. If you got close enough (inches) your bow wave would push on the person in front. At any sane distance, the effect is below negligible. You would be pushing with sound waves. ie, you can ignore it.
If you stand on the side of the highway, you can get an idea of how trucks affect the air. They are moving LOTS of it...and it's all going in the same direction they were. Now take a car like my Escape (CD = 0.40). I was having trouble keeping at the speed limit today because I had a 10-15 mph wind coming straight down the highway in my face and I'm just not used to pushing the pedal that hard. Reducing the relative wind velocity by 5 mph by following a truck at a safe distance will make a difference. I'm going to be driving to Florida this summer. That'll be 30+ hours to practice the art.
Drafting does not slow the person in front. If you got close enough (inches) your bow wave would push on the person in front.
I've felt that.... cruising along... suddenly your speed picks up by 3-5mph...and you look in your rearview and read renilthgierF
I remember The RoadWarrior..To understand who he was, you have to go back to another time..the world was powered by the black fuel & the desert sprouted great cities..Gone now, swept away..two mighty warrior tribes went to war & touched off a blaze which engulfed them all. Without fuel, they were nothing..thundering machines sputtered & stopped..Only those mobile enough to scavenge, brutal enough to pillage would survive. The gangs took over the highways, ready to wage war for a tank of juice
What are the general rules for side-drafting? There must be a point where it can actually hurt you because you will be in a wave of compressed air. If I'm back far enough, the benefit must be close to that of drafting directly behind.
Geese fly in a V formation, but is it for drafting or more for navigation and staying together as a flock?