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I am currently a student in an Engineering Design and Development, Project Lead the Way class. As my final project, I have decided to improve cruise control by adding a mode where engine load instead of speed would be the constant(DWL). I would be testing this system on my personal car, a 1996 Pontiac Sunfire 2.2 liter 5 speed with factory cruise. This mod would be something that piggybacks on the stock GM cruise. I need to have a survey to prove my idea is good and going in exactly the right direction. Thank you for your responses.

http://www.surveymonkey.com/s/SC88BDM

Hi PLTWstudent,
Welcome to CleanMPG. I will take your survey. If you want to read some great info on how to improve your fuel efficiency, go to the link in my sig.

Good Luck on your project!

I just took your survey. A load base cruise would be great for people that like to use the cruise. The current speed based cruise is inefficient for hypermilers.

What school are you at that is involved with PLTW?

I took it as well. Welcome, and good luck! :)

Thanks to everybody who took the survey.

I just took your survey. A load base cruise would be great for people that like to use the cruise. The current speed based cruise is inefficient for hypermilers.

What school are you at that is involved with PLTW?

The main idea being that it is safer to DWL if the car does most of the work for you, allowing you to pay more attention to the road and less to the vacuum gauge.

This sounds like a great idea!

You mention vacuum gauge: is that how your mod would work?

Years back I hooked a "PassMaster" to a few of our cars: basically a switch controlled by vacuum. The switch was closed as long as decent vacuum was supplied, and open when vacuum dropped. You spliced it into the power lead to the AC compressor.

Basically to shut the compressor off momentarily during heavy load. Worked pretty good ;)

I have also give this type of cruise control a bit of thought. At first blush it appears to be an attractive idea, but there are some practical problems. In chosing to set the engine at a constant load, it is assumed that that load is an "efficient" load on the BSFC chart. In that case, it is a rather high load on a relative basis, and corresponds to high output power. This presents obvious problems, if such a cruise control were kept engaged on level and downhill sections, the vehicle would travel at excessive speed, increasing aerodynamic losses. So, the pure load requlated way doesn't actually work in practice because of widely practical driving conditions. One work around to that issue might be an automatic override of all throttle when speed becomes higher than some predefined limit. Even if loads lower than ideal were selected, the problem is only slightly mitigated.

I think that these circumstances mostly mean that we design vehicles with engines which are too large and too powerful, and that we gear them too high. The "excess" of power is desired for crisp acceleration, high cruising speeds, and greater load hauling capabilities, not such trivial considerations.

Your idea would probably be more successful in a small displacement car, with limited power and fairly high gearing. There was XFi which I believe fullfilled these constrains. A first generation Honda Insight, with one of the devices for locking out hybrid assist might also work.

It is true that a cruise control such as you describe "might" perform fairly well in modest terrain, but even there the variations in speed might be unacceptable. I personally think a well trained right foot and a good set of eyes on the upcoming terrain would do a better job. But it is JMHO. It is an interesting topic and I look forward to your results and perhaps some perspective from others.

........ I personally think a well trained right foot and a good set of eyes on the upcoming terrain would do a better job. But it is JMHO. It is an interesting topic and I look forward to your results and perhaps some perspective from others.

I'm in total agreement with Jim. The human brain can process a lot of information out on the highway that a crusie control can't come close to matching. It just needs to be engaged with right out come in mind.

But they have some cars driving around without drivers that are doing pretty well on test tracks so given enough tax dollars they might get close.:flag:

added 6-8-2011
found survey closed