Acceleration - how hard?

[Eddles]

Simple question. How hard should I accelerate? As my FE is nearly zero when accelerating, the logical conclusion is to accelerate as hard and as fast as possible to my desired cruising speed, obviously assuming there is nothing in front of me, e.g. traffic lights, possible events that I will need to slow down for. But this sounds like a whole load of fuel would be used up, or is it just being counter-intuitive?

Or is my logic faulty, and I should be accelerating as gently or possible? Or somewhere in between?

Thanks very much for your time in advance!

[abcdpeterson]

I have read a lot of people recommending engine load around 80, and shift around 2k.

I have found load in the 70’s and keep rpm’s under 2150 works best for my car.

[diamondlarry]

I think I'm with Allen on this one. Moderate acceleration seems to give me the best results. I've been thinking about doing some calculations on how much fuel is burned overall during a pulse. I would be using the GPH feature of the Scanguage and a stop watch to see how much fuel is burned to go from a lower target speed to a higher target speed during my P & G routine.

[PaleMelanesian]

Call me a salesman for Autospeed.

http://www.autospeed.com/cms/A_110216/article.html

[abcdpeterson]

that artical is great,
a lot to understand on a 1st read, I find my self rereading that one every month or so.

[jimepting]

It is indeed a GREAT article. I've read it several times and I have a general understanding - I think. But, I am always left with some of the same questions. The main question I have is, how do we apply the article results to our individual cars. The article clearly indicates that best BSFC is going to occur at different loads and different RPM for different cars. In other words, there are different graphs for each car. How do we figure out, except in a very general sense, what the graph looks like for our own cars.

It would seem that one could gather experimental data with the SGII on GPH times time, as diamondlarry proposes. By doing that at different loads, one could graph the results and spot the optimum. As in all testing, a level road and a windless day would be required. In his case, it would seem that the electric assist might complicate the results, but I know very little about Prius.

[PaleMelanesian]

My personal experience shows the rainbow colored chart to be fairly accurate for my car.

There's also a thread at ecomodder where people post whatever charts they've found. http://ecomodder.com/forum/showthrea...-got-1466.html

[jimepting]

Yow Andrew, you are just a fount of great information! The 1.0L Metro engine is one of the engines I was most interest in an there is the info I was seeking. I do note from the chart that the "sweet spot" is very narrow in terms of torque, or load, so driving a 1.0L Metro in the sweet spot, over a wide range of conditions, is gonna be very difficult. Installing the long gear and doing a lot of shifting would probably be required. I think some experimentation, as diamonlarry suggests, would help nail the actual load, but without SGII capabilities, even that approach has problems.

The site you ref has no info on other cars so apparently this type of vehicle specific information is hard to come by.

[steveyfrac]

The map from autospeed is exactly what i was thinking should happen. Lower gear, and higher throttle increases peak cylinder pressure, which tends to improve thermodynamic efficiencies of any cycle. Nice to have suspicions confirmed. Thanks for the post.

[hummingbird]

So what is the practical implication of this article for me? Is it better to floor it while pulsing? Does this not go against the adage "accelerate like a granny"?