How to get 46 mpg

[branderson3]

No not coasting down a hill....

Was on 465 in Indy, heading up to Lafayette, and thought I would try a little "drafting" out. Got about 2-3 car lengths behind the fastest semi I could find (about 62 in a 55) and reset the DIC. Went down the road about 10-12 miles like that before I peeled off, with the DIC reading 46 mpg!

So yeah, not the most fun thing to do. Especially if you are impatient like me. But its something to know if you are ever running out of gas or broke! Had the sunroof open and did a little aero test, not scientific or anything but the handometer siad it felt like about 30-35 mph.

[Coupe_GTP]

if you only went that short of a distance the dic was still calculating what your mpg was so that isn't a accurate number really. mine has stayed at 50 for a minute when I have reset it.

[WS6 RACING]

I tried that going to the Grand Canyon. Unfortunetly the rocks that were kicked up made it not worth it.

[CoPed]

A few years back when my father and I drove up to Ontario we were doing this.... we were in a pickup too so it really helped out.

We'd be touching the brake too because (with a load in the pickup) we kept gaining speed on the rig in front of us. We only had to hit the gas on an incline or to re-accelerate to the speed of traffic.

No dic in the pickup then, so no numbers, but tank wise, probably saved us at least one almost 2 full fill ups.

[gearjammer]

Do not believe that MPG reading. I noticed when I reset that it always gives some crazy reading.
Best way to check is too fill gas completely then reset trip meter drive then refill gas and divide miles driven by gallons for a more accurate reading.

Drafting behind a truck will not add 20 MPG no way. Aint gonna happen

[gearjammer]

A few years back when my father and I drove up to Ontario we were doing this.... we were in a pickup too so it really helped out.

We'd be touching the brake too because (with a load in the pickup) we kept gaining speed on the rig in front of us. We only had to hit the gas on an incline or to re-accelerate to the speed of traffic.

No dic in the pickup then, so no numbers, but tank wise, probably saved us at least one almost 2 full fill ups.

Wow you are so full of crap. A truck will not create enough draft to pull you along. I think others will back me up here

[GTPGuy82]

For the first time ever last week, I reset my mpg and drove about 60 miles to the shore. When we got there, my DIC read 25.6, which is the highest I've ever gotten.

[kgeier82]

they did this on myth busters.

came up with some good data, NO WHERE NEAR 90-100% gain in mileage.

your test is obviously flawed if you only did it for a short short time. considering it takes the DIC around 100mi to get somewhere close to where ever it usually reads.

if i remember right, the highest they saw was at a distance of 5-10ft around 20% increase in mpg

[kgeier82]

http://www.env-econ.net/2007/06/mythbusters_and.html

some numbers, roughly

[CoPed]

A few years back when my father and I drove up to Ontario we were doing this.... we were in a pickup too so it really helped out.

We'd be touching the brake too because (with a load in the pickup) we kept gaining speed on the rig in front of us. We only had to hit the gas on an incline or to re-accelerate to the speed of traffic.

No dic in the pickup then, so no numbers, but tank wise, probably saved us at least one almost 2 full fill ups.

Wow you are so full of crap. A truck will not create enough draft to pull you along. I think others will back me up here

You've never driven a full size pickup loaded down with a piano, 2 highboy cabinets, 4 mattresses, a full tank of gas and other shit before have you.

If you get on even a 1/2 degree downward grade with a full size trailer in front of you, you will gain ground.

Call bs all you want. But I am not one to bs.

[branderson3]

A few years back when my father and I drove up to Ontario we were doing this.... we were in a pickup too so it really helped out.

We'd be touching the brake too because (with a load in the pickup) we kept gaining speed on the rig in front of us. We only had to hit the gas on an incline or to re-accelerate to the speed of traffic.

No dic in the pickup then, so no numbers, but tank wise, probably saved us at least one almost 2 full fill ups.

Wow you are so full of crap. A truck will not create enough draft to pull you along. I think others will back me up here

Wrong. Honestly, I know the DIC isnt going to be completely accurate (usually about 1-2.5 mpg off for me). But 10 miles was enough for it to "settle" down and it at least gives a point of comparison. May have been 40mpg in reality, but still abnormal for sure.

The truck was not "pulling" me. I was close enough for him to break the airflow around my car, and yes that will significantly reduce the drag if the turbulent wake flow is directly on the car. If the airflow were 35mph instead of 60, the drag would be about 1/3. I dont know if this was the case but just a guess. That would be enough for actual mileage in the 40mpg range at 60-62.

Btw, I have a '05 3.5 and yes it does usually get very good gas mileage. Going 70mph on the same ~70 mile trip DIC indicated 38.6mpg. This is with very little wind, relatively low humidity, and temps in the high 70s. I dont get this all the time, usually indicates 32.7-35.6 on the highway in the spring/summer/fall and drops of in the winter.

I will try to do this agian and get some video. My camera only takes 30 sec clips at a decent resolution , so be prepared for a clip show.

[branderson3]

they did this on myth busters.

came up with some good data, NO WHERE NEAR 90-100% gain in mileage.

your test is obviously flawed if you only did it for a short short time. considering it takes the DIC around 100mi to get somewhere close to where ever it usually reads.

if i remember right, the highest they saw was at a distance of 5-10ft around 20% increase in mpg

i agree, it was flawed. I've spent enough time messing with wind tunnels in lab to know! I would have to do many trials for thousands of miles to get a true idea.

[gearjammer]

A few years back when my father and I drove up to Ontario we were doing this.... we were in a pickup too so it really helped out.

We'd be touching the brake too because (with a load in the pickup) we kept gaining speed on the rig in front of us. We only had to hit the gas on an incline or to re-accelerate to the speed of traffic.

No dic in the pickup then, so no numbers, but tank wise, probably saved us at least one almost 2 full fill ups.

Wow you are so full of crap. A truck will not create enough draft to pull you along. I think others will back me up here

You've never driven a full size pickup loaded down with a piano, 2 highboy cabinets, 4 mattresses, a full tank of gas and other shit before have you.

If you get on even a 1/2 degree downward grade with a full size trailer in front of you, you will gain ground.

Call bs all you want. But I am not one to bs.

I drive a truck for a living buddy. All that stuff in your truck sounds like your name might be Fred Sanford.
I have pulled loads weighing 100,000 pounds a little more than your truck load

[ElecBlueG6GT]

Feel the love.
Drafting saves gas period. How much depends on distance traveled. I've drafted a semi before, problem is, if he brakes suddenly, it's too late to stop by the time you know.
BTW, 65 and 52 go to Lafayette, you coming from the east side of Indy?

[branderson3]

Feel the love.
Drafting saves gas period. How much depends on distance traveled. I've drafted a semi before, problem is, if he brakes suddenly, it's too late to stop by the time you know.
BTW, 65 and 52 go to Lafayette, you coming from the east side of Indy?

NE side (castleton/fishers area), went from allisonville rd exit to 865 exit.