Driving for Economy....Acceleration???

[Capt Joe]

While reading the thread on "Hypermiling", I got to thinking about ways to drive my MH to increase my fuel milage.

While on the road, I generally have my instantanious MPG readout active. This really gives me a quick indicator of just what a little bit of pressure on the gas pedal does to you fuel burn as well as what even a slight incline does as well...and, we've all seen the pictures of the indicators while coasting down a hill and showind MPG as much as 75mpg and higher...much higher.

Well, that got me to thinking about accelerating from a stop in our heavy RVs. Most of the time, I take the slow and smooth acceleration route and many times I see the instantanous MPG readout down in the 3 mpg or lower range even while trying to feather the gas pedal real easy. Then at times, I'll just keep up with the traffic and don't really notice a whole lot lower MPG numbers...and the low numbers seem to be there a lot shorter time.

So, which way of driving should give the best fuel economy...in the long run...., the slow and steady or the harder more rapid getting up to speed? Now I'm not talking about putting the pedal to the metal or anything like that, just keeping up with most of the traffic, which is pretty easy to do in my 32V Brave with the 8.1 and Allison but I do have to put my foot into it a bit.

Any thoughts, especially any with test or data to back up your thoughts, will prove, IMHO, to be interesting and hopefully beneficial.

Discussion, please....

[Capt Joe]

While reading the thread on "Hypermiling", I got to thinking about ways to drive my MH to increase my fuel milage.

While on the road, I generally have my instantanious MPG readout active. This really gives me a quick indicator of just what a little bit of pressure on the gas pedal does to you fuel burn as well as what even a slight incline does as well...and, we've all seen the pictures of the indicators while coasting down a hill and showind MPG as much as 75mpg and higher...much higher.

Well, that got me to thinking about accelerating from a stop in our heavy RVs. Most of the time, I take the slow and smooth acceleration route and many times I see the instantanous MPG readout down in the 3 mpg or lower range even while trying to feather the gas pedal real easy. Then at times, I'll just keep up with the traffic and don't really notice a whole lot lower MPG numbers...and the low numbers seem to be there a lot shorter time.

So, which way of driving should give the best fuel economy...in the long run...., the slow and steady or the harder more rapid getting up to speed? Now I'm not talking about putting the pedal to the metal or anything like that, just keeping up with most of the traffic, which is pretty easy to do in my 32V Brave with the 8.1 and Allison but I do have to put my foot into it a bit.

Any thoughts, especially any with test or data to back up your thoughts, will prove, IMHO, to be interesting and hopefully beneficial.

Discussion, please....

[Chickadee]

Capt. Joe: Hey, thanks for the post. I've wondered the same thing. I too keep an eye on the "Fuel Inst." (MPG readout). Ain't to encouraging pulling upgrade when readout drops down to 3 mpg, BUT, WOW!...it's fun on those downgrades when showin 75, 85, 95 and into the hundreds mpg's. Guess there must be MORE upgrades in this country than downhills, since that dang "AVE mpg" doesn't improve much. Maybe better route planning would help...eh? (...let's see now...ofcouse everyone knows headin North into Canada and Alaska HAS to be UP-hill....then headin South must be downgrade. But this country is mostly laid out East & West....soooooo, awwwww, I'll NEVER get it figured out ) Steve

[read & learn]

If you really want to see what hypermiling is all about google it. There are some very safe ways of increrase mpg.
ex: look ahead for red lights and start to coast and try not to have to stop completly as it takes more fuel to get back up to speed from a complete stop than a rolling slow down.
Remember there are many unsafe things that hypermilers do.

[tmar10]

We knew we were buying fuel loving beasts when we signed on the dotted line. My driving habits have not changed with the increase in fuel costs or changing economy. I drive at a reasonable and safe speed, use a little common sense and fill up before I reach a 1/4 tank.

[Capt Joe]

I certainly agree that we knew about the fuel guzzling properties of our RVs and I have not really changed my driving habits very much either.
I have always tried to drive in a manner that will return a reasonable economy. I think that while there are other things going into the price of fuel, the laws of supply and demand do figure into the equation and I certainly do feel a responsiblity to do my part by burning less fuel thereby decreasing demand in helping to keep the price down from the $4 per gallon we were paying on our trip to the Keys back in June. Getting ready, suppose to leave this afternoon, for a 1000 miler (with a change due to our sister in laws father's death yesterday will probably now turn into a 1400 miler) and the current gas prices will certainly make it a lot less expensive. No complaints...As I use to tell my boat customers..."If you are going to play, you GOTTA PAY".
Which brings me back to my original question... Is it better to use the egg between my foot and gas pedal to get up to cruising speed or be a bit more aggressive in acceleration to get to cruising speed more quickly?
Inquiring minds want to know....

[RedneckExpress]

Personally, I use the egg method. You're also reducing the strain on the automatic from heat generation cause by spinning the torque converter in the open position, or at least it is in my case, a 5.9L V8 Gas engine can only accelerate 11-12k lbs so fast.... It takes me a mile or two to get up speed on most occasions. Been more than one time where I'm having to merge into the slow lane at 45 mph. Those acceleration lanes always seem to get shorter every time they build a new interchange....

[RVDriver]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">So, which way of driving should give the best fuel economy...in the long run...., the slow and steady or the harder more rapid getting up to speed? Now I'm not talking about putting the pedal to the metal or anything like that, just keeping up with most of the traffic, which is pretty easy to do in my 32V Brave with the 8.1 and Allison but I do have to put my foot into it a bit. </div></BLOCKQUOTE>

Capt Joe,

After you overcome rolling friction, (RV will Coast) any hard accelerating would result in no additional increase in mpg. IMHO Enough pressure on gas pedal to obtain crusing speed should be all thats required. (in other words) "If you are not gaining speed, and MPG readout is decreasing you are wasting fuel". Yes it will drop to 3 or so mpg, but if you are gaing speed at 3 mpg don't apply more pressure on the gas pedal.

Now that said, the only time I have mine on "Instant Read Out" is by mistake, I always drive wilth "Average Read Out" BUT I really watch it when going up an incline!

[dieselclacker]

I accelerate from stops with the egg method, unless going onto an interstate or freeway on ramp. Going too slow to merge into traffic is really dangerous. Also I do not place too much stock in the MPG shown on the readout in either instantanious or average, it is known to be in accurate. Agree with RVDriver above, as long as you are gaining speed, don't acellerate, unless of course you are drag racing with a Ford
product.


Dieselclacker

[Ray,IN]

Although not directly addressing the original question, this horsepower calculator is informative to play around with and realize the effects of inclines, which may then be compared to acceleration rates. Just compare the HP requirement of a-say- 6% grade at 50mph to HP requirement to accelerate from 0 to 50mph.