best highway ecodrive tip?

[modmonster]

hi

i do a lot of motorway driving now and i was wondering what is the best thing to do.

i can think of:
driving @ 55mph
driving behind a big truck (drafting)
pulse and glideing

Have i missed anything?

[99metro]

Inflate tires to sidewall rating.
Coast A LOT at every opportunity.
Don't haul around unnecessary stuff (make your vehicle light).

[modmonster]

whats worth taking out of your vehicle? im thinking back seats, spare tire, only half fill tank.

[Brian03cav]

i dont think i would take out the spare, i mean yes that would save weight, but then you have safety to consider.

i've found great gains with keeping top speed to 65 or under (60mph seems ideal for my car.) also, like 99metro said, coast alot and fill those tires! another thing is keep your windows closed, use fans first, and if too hot use a/c. not using a/c saved me greatly as well.

[whokilledthejams]

Block off as much of your grille as is practical (i.e., without running too hot or having the fan come on too much), and see what you can do to smooth out the bottom of your car.

[Lazarus]

Driving with load on the hills. Route palnning, departure time if possible and remove any unnecessary drag. Roof rack, Bicycle racks, etc.

[thebrad]

Use Scangauge II to stay at a constant throttle position (TPS), for me 14-17%

Also from my experience EOC/P&G doesn't work on the freeway in the 55-70mph range. This is what led to my discovery of locking in TPS at ~15% and driving at 50-55 mph.

[Z man]

On flat highways, you can't really coast too well. But 55-65mph is perfect, and its nice when trucks get in front and behind you. In draft, I will hit 70 occasionally because its worth it to keep up with a big tractor trailer.

[SVOboy]

Driving with load is definitely important on the highway. Also, don't draft! Crashing is real bad for fuel economy,

[Z man]

Originally Posted by SVOboy

Driving with load is definitely important on the highway. Also, don't draft! Crashing is real bad for fuel economy,

Yeah but playing close attention and driving about 4 car lengths back isn't so bad. Plus, it you leave a big enough gap, someone with ruin your safety cushion by getting right in the gap you made.
DWL is nice for sure.

[modmonster]

but i saw a picture of the stream lines on a truck somewhere on this site and the low pressure didn't extend that far back. you have to drive right behind the truck to see gains = unsafe.

is driving 4 car lengths back from a truck gonna save you anything or is it just the lower speed that saves you?

[99metro]

4 car lengths is still too close. At 65mph, you should be three to four of HIS lengths behind him, or about 200 feet, at the closest. Do the math so that you are no closer than 2 seconds behind him. I would love to find a truck going 50-55 mph so I could get two or three of his lengths behind him (2 seconds). If he drives any faster, I'm better off doing P&G.

[superchow]

I usually find it safer driving behind semi trucks. They can see further down the road and change their speed with greater consideration for efficiency, i.e. slower acceleration and braking. Also, if the truck decides to do an emergency braking maneuver, unless it is very light, should be far greater than that of a light (and well maintained) passenger car.

I have also achieved great mileage following a speeding vehicle (not too closely of course) because I presume their wake becomes larger at higher speed. However, when that person slams on their brake, their car's/truck's/SUV's braking distance is much shorter, and as a result I feel less safe following them.

The trick for me is to look down the road much further and anticipate traffic flows before they even happen. For example: ever noticed how during a traffic jam the traffic always speeds up right after an off-ramp? It's obvious "herd" behavior. "Oh - more space! I'll floor the accelerator to prevent the person beside me to merge into my empty lane!" Then everybody reaches the on-ramp of that exit and there's mass braking because the traffic bunches up again. Just that observation saved me from a few accidents already.

Of course, it helps if you're actually watching the traffic instead of planning your evening...

Drafting comes naturally to me now, and I use my wife as a "safety gauge". She tenses up when it's unsafe - for her. Four cra lengths has always been a pretty good distance to me, but I get closer when the truck driver seems to be driving attentively.

[modmonster]

do you ever get that feeling your being watched by the truck driver? they often weave side to side so they can see you in their mirrors when 5 car lengths back. is there a rule of courtesy between truck drivers where they take turns to draft each other. i've often wondered if they think me only drafting from them is selfish?

[superchow]

Originally Posted by modmonster

do you ever get that feeling your being watched by the truck driver? they often weave side to side so they can see you in their mirrors when 5 car lengths back. is there a rule of courtesy between truck drivers where they take turns to draft each other. i've often wondered if they think me only drafting from them is selfish?

Of course, but from their perspective, if I keep a respectful distance then I am actually helping their aerodynamic shape too. I had everything from a truck driver varying his speed by 15 mph to discourage me from drafting to blinker flashing as a "thank you". There are plenty of truckers that waved back at my wife (in the passenger seat) when we passed them eventually. (No cutaneous over-exposition was involved, mind you!)

This close to made my day: Courtesy on the highway! Ever blocked traffic behind you to give a trucker some room to merge?

If we all drove as if one's mother or Jesus or loved one, etc. was in every other vehicle, then accidents would turn into the exception. Imagine it is YOUR child playing on the street when you speed past it going 50 in a 25. (OK, rant over now...)

[Axaday]

I've made two out of town highway trips since getting the scanguage. I thought pulse and glide between 65 and 55 would be really good and that's what I did the first time. It got me great mileage.

But a month later I decided to try regular old cruise control set on 55 to see how much better the P&G was. The cruise at 55 was a couple MPG better and was, of course, much easier. Next time I'll try 50.

[Tourigjm]

I find P&G/DWL to be the most effective. I pulled down 49.54 MPG on a 341 mile trip on all hwy by doing just that. My average speed was about 52 mph (it was a long day) No Drafting (My car was full of stuff for school too, so it was significantly heavier.) I normally get around 40 MPG's with a mix of hwy/city driving.

[modmonster]

is drafting worth it or is driving slow better?

[Axaday]

Originally Posted by modmonster

is drafting worth it or is driving slow better?

I wouldn't presume to judge you, not knowing you, but I think more people think they are a good enough driver to do it than actually are. It is risky enough that I don't myself.

[PaleMelanesian]

Originally Posted by modmonster

is drafting worth it or is driving slow better?

I've tested it in my Civic and Odyssey. The results were similar. Drafting (3 seconds back) gave about the same benefit as driving ~6-7 mph slower.

I like to give myself enough space to stop if the truck was suddenly not moving at all. My car's stopping distance = my drafting distance. Let's say that's 150 feet. At 60mph, that's about 2 seconds back. Only time I'm closer than that is when they pull in front of me.

My highway advice:
Manual trans - P&G. 45-60 mph P&G is worth about 70 mpg in my civic in good weather
Automatic - DWL. 60 mph DWL in the Odyssey is worth about 29-30 mpg. (rated 18/25 old, 16/23 new)