Increase gas/mileage by doing this.

[PCY]

Got on a job to travel from Beaumont to Houston (89 miles), traverse through city traffic jam complications (67 miles), then Houston to Baton Rogue (245 miles). A total of 401 miles with 3/4 tank of gas got it done.

I watched mythbuster's episodes and remembered that Grant was trying to tailgate an 18 wheeler truck for something else; they conveniently found out that wind drag was reduced and gas/mileage increased by following incrementally closer distances behind the 18-wheeler truck.

Long story short, I decided to fill up a full tank and tried this out. On the way from Beaumont to Houston, I spotted an 18-wheeler with low splash guards in the last row of wheels (so that rocks wouldn't fly directly at my car). I kept a 5-7 car distance (about 150 feet) behind the 18 wheeler. Traveling at a pretty consistent 70 mph on Highway-90 all the way into Houston, about 89 miles. Then my business took me from one end of Houston to another with many stop signs and redlights. I was doing 45mph at times, other than stopping for traffic. In city travel is 67 miles and a big part of it was a traffic jam. Then From Houston to Baton Rogue of 245 miles, I spotted and followed another 18 wheeler at around 70 mph again. At times, I'd follow that truck to pass slow vehicles and got to 75 mph a couple times. Switched to follow other 18 wheelers at my convenience at times.

When I reached a gas station in Baton Rogue, trip meter shows 401 miles and 4 blocks of gas left in the indicator. It's about 1/4 tank left. Pumped gas again and took 12.432 gallons on it. I'm dividing 401/12.432 and got 32.255 miles per gallon of gas out of this trip. I'd say it's 75%highway and 25% city.

The moral of this story is that past 60 mph, any car would be consuming extra gasoline pushing through stale air resistance. Going behind a big rig will allow the car to shuttle through compromisingly favorable turbulence and allow car to push against a much smaller load of air drag. Especially this Rogue, from the way it looks, this inline-4 engine can definitely use a lift from the 18-wheelers. The bad thing is: I find that 18-wheelers only travel fastest at around 70-73 mph. If I spot a good truck at higher speeds, I'd jump on that wagon. So conclusively, it took me about an extra hour longer to complete this trip because I usually drive at 80-85 mph. And that range had yielded me 23 miles per gallon on the freeway with this Rogue.

This method is from my personal experience only. Your results may vary, and please do not follow too closely to tailgate any other vehicles. I'm a very good driver and 150 feet of distance is plenty for me to handle. Since gasoline price is such a big deal nowadays, I just thought to share this with you guys and help you save money.

EDIT: By the way, I got a SL AWD with Sunroof/Splash/BmpGuard/KickPlates/RubberFloor&CargoMats and a bunch of work equipment at around 220-240 pounds together. And I weigh 160 lbs.

-Peter-
Modified by PCY at 11:24 PM 3/21/2008

[philipa_240sx]

Just to demonstrate how dangerous this is, at 70mph you cover 102 ft/sec. At 150ft you have just barely 1.46 sec distance behind the truck. It takes the average human 0.75 sec to react to an emergency braking situation and another 0.75 sec to move thier foot to the brake pedal. That's a full 1.5 sec before you start to slow down! If the truck does any sort of abrupt braking, emergency manouvre, or even tire delamination, you would likely hit it or the debris by the time you react!

Please be safe out there and don't tailgate. I'll gladly pay a few extra $$$ at the pumps and save my bacon!

[Etch]

I agree with your figures, although a tractor trailer is not going to be making an abrubt stop due to its weight. The danger of hitting tire tread would be more what I'd worry about, but that would be more swerving than braking. I wouldn't recommend tailgating any vehicle to save gas.

On a side note, I like the fact that PCY mentioned the low mud flaps. It brings up another interesting point. The worst vehicle you can follow is a pickup truck without mud flaps. Not only do you have more chance of being hit by a rock being thrown from the wide exposed area of the truck's tires, but trucks are also most likely to have rocks stick in their tread since that would be the most common vehicle to take to unpaved areas like construction sites. I myself have a pickup truck and live down a gravel road and several miles down the road I hear a rock or two hitting the underside of my truck. So don't get behind me!!

[BrianV]

In my MDX I can go from 21mpg to 26-27 by doing the same on I-10 going into Houston.

I generally try to find a big truck like an Expedition or Suburban and do that and still get 25ish. Getting behind any vehicle that moves air will help significantly.

[PCY]

Just to demonstrate how dangerous this is, at 70mph you cover 102 ft/sec. At 150ft you have just barely 1.46 sec distance behind the truck. It takes the average human 0.75 sec to react to an emergency braking situation and another 0.75 sec to move thier foot to the brake pedal. That's a full 1.5 sec before you start to slow down! If the truck does any sort of abrupt braking, emergency manouvre, or even tire delamination, you would likely hit it or the debris by the time you react!

Please be safe out there and don't tailgate. I'll gladly pay a few extra $$$ at the pumps and save my bacon!

I totally agree on the reaction time calcs you put out here. While I'm trying to milk as much gas/mileage as I can, I tried to follow the 18-wheeler as close as 2 car length away, and that was too dangeous for me. I backed all the way out to about 5-7 cars away and found myself to be comfortable and was really focused to react to the 18-wheeler's speeds.

That's why I specified for people to reconsider if they are going to try this. But the bottom line is, even at 400 feet distance (15-18 cars away), the gas/mileage would already have improvements according to what they find in Mythbusters. Grant got as close as 40 feet, IIRC, and got up to 40 miles per gallon in his test car (don't remember what car it was, but it must have EPA in the 20's). Anyways, I am easily capable of handling 5-7 car distances away without a glitch for the whole 4 hours from Houston to Baton Rogue, and milked tremendous gas/mileage out of it. I'm pretty sure that even 200 feet distance would yield good results, too.

While you are willing to pay extra bucks for gas, I chose this SUV mainly because of the gas/mileage, so I'd work it to milk more if I can. If gas/mileage wasn't an issue, I'd take a Murano over this Rogue anytime. Plus, I didn't even have to pay for this vehicle at all, my company gives me 750 bucks a month to cover my transportation needs, whatever I can save from that amount, it's for me to keep. Hence, milking a few more miles at a manageable distance isn't that much a risk for me, plus, driving at 70 mph like that is very easy and nice. It gets more dangerous when I got the kick of adrenaline and exceed speed limits all the time.

-Peter-

[Beagle_Hauler]

And I used to do it 20 years ago when it was fairly popular. Fun thing was to flash my headlights at tractor trailers (sic: "18 wheelers") so they could pull in front of me, and they would flash their tail lights as a thank you. Those were the old days. When my wife was a youngster, her dad did it all the time between LA and Las Vegas. It was a fairly common thing back then, however, I work for our transportation/delivery fleet division for a concrete company. DO NOT DRAFT! I do not recommend you draft behind those rigs. In the modern world, each of those 18 tires cost anywhere from 500 to 1000 bucks brand new. That's brand new folks. Times 18. Most trucks use what's called "retreads". They simply tear off the old tread leaving the sidewall and a minimal amount of tire, and glue on a new tread. This only costs 200 bucks or so, each tire. Times 18. It's not as safe and does not last as long as a brand new tire would. That's why you see those chunks (or sometimes whole) treads all over the freeways and highways. They weigh alot, say 20 pounds. Would you want a 20 pound weight flying back at your windshield at 70 miles per hour? Oh some of you say that's not alot, ok, how about a bowling ball (they are 16 pounds...) at your windshield at 70 miles per hour? Now it seems it's not so good an idea. Still not convinced? You've all seen what one little pebble does at 50 miles an hour to your windshield, right? Puts a crack in it or at least takes a divot out. Those weight what, an ounce if that? You risk having a 20 pound hunk of rubber coming off a tire, and trust me, they come off and back real fast, and going through your windshield if you follow behind or alongside a tractor trailer. And the only thing stopping the rubber tread after it smashes through the windshield is your face. Or the face of your spouse or child. This is the reason I stay way back, or way in front of tractor trailers. Also you should watch out for large rocks that are caught in the "dualies". Thats what you call two tires side by side, as on most axles of those trailers. Our trucks go off road, and the tires flex and pick up small boulders (5 to 10 pounds each), that are bigger than your fist, they get caught in between the sidewalls of the two tires. When they get up enough speed once back out on the highway, the centrifugal force is enough to launch that rock from out between and back behind the trailer at very high speed. Our 20+ truck fleet causes at least 2 broken windshields per month (mostly pebbles and small debris from our empty trailers, pieces of broken pallets, nails from said pallets, concrete etc, they are flat beds, not enclosed "vans" by the way) and those are just pebbles folks. Please be very cautious if you decide to draft and keep in mind you should look for large rocks trapped between the duals and for worn out or old looking treads on those tires. Yes, I hear some of you counter arguing right now, and the chances are very low that anything will happen, but it's still high enough that I don't risk the life of my wife or my children and I will gladly eat the extra MPG's to stay that much safer. Plus we'll enjoy the wide open view you get when not drafting behind a trailer... I honestly hope I've saved a life today. If you draft, be very very careful. But if you ask me, it's not worth the risk. It's state law that our truck drivers inspect inbetween the duals of their tires when leaving off road and onto paved road. In fact, last summer a tourist was killed when a rock came out from between two dualies (it wasn't our truck, but some careless truck driver who didn't inspect his tires for rocks). That may be one death out of thousands of trips that big rigs take every day, but IT DOES HAPPEN. So play it safe, please!

Modified by Beagle_Hauler at 3:43 PM 3/23/2008

Modified by Beagle_Hauler at 3:43 PM 3/23/2008

Modified by Beagle_Hauler at 3:49 PM 3/23/2008
Modified by Beagle_Hauler at 3:50 PM 3/23/2008

[flybooey]

I used to do it occasionaly on my sportbike b/c the wind protection on those bikes are only good if you are laying on the gas tank. It was just nice to take a break from the wind pounding on you.

Then I followed a rig into a rest stop that i had been drafting and when he pulled to a stop i noticed a intact house brick that was jammed between two of his wheel on the rear on the trailer.

I stopped drafting rigs.

[shavimusha]

I would not follow truck behind even if my rogue goes 100 mpg ! You said you where afraid of rocks so you stayed behind rocks are lest you need to worry about ! I got hit with leaf spring witch fell of the truck and trust me my maxima door looks very bad ! Plus trucks heave engine brakes which make them to almost stop after you release accelerator and during this process brake lights do not come on so before you know it you would be kissing truck on lift gate ! And most important they just don’t see you when you drive behind them !