Thanks guys!
I appreciate your responses and all the great information...
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Originally Posted by NeilBlanchard
What are your tires inflated to? How is the alignment? Have you checked for brake drag?
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Before discovering the EM site, I was at 34psi. I went up to 46psi and noticed that I consistently rolled further and faster on my regular coasts. I'm going to bump it up to 50psi on my next trip to the station. (My sidewalls are 51psi max.)
Alignment is good. Had it done in January just after buying the car.
I haven't checked for brake drag, although I've read it in other posts here. Any advice on how to do that? Until EcoModder, the only thing I knew about cars was where to put the gas and oil. Oh...and how to add the blue window washer fluid! (OK, maybe I wasn't *that* bad. But pretty close.) So I have no specialized auto tools or knowledge. Is it just a matter of jacking up the wheels one at a time, spinning them and listening for rubbing parts? Should I expect a certain number of rotations?
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Originally Posted by aerohead
I think Peter hit on it.
If you look at the SAE protocol for coastdown tests you notice that the aero drag portion isn't out of the picture until down around 20-mph,where rolling resistance basically dominates the road load from there on down.
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I had guessed that 35MPH or there abouts was the speed at which the aero wouldn't be a factor. But after reading everyone's explanations about roller bladers and bikers, I can see where it still makes a difference at lower speeds. Otherwise the serious skaters and bikers wouldn't be wearing those aero-suits and aero-helmets, I guess.
And I didn't even take into account how headwinds add to the relative speed of the car to the air it's moving through.
Okay...so every little bit that can be done to help cut through the air better means that the speed where rolling resistance becomes the limiting factor is lowered. I think I've got a much better understanding of it now.
Appreciate all of you who took the time to help me. And have to add a special thanks to aerohead for the multi-part seminar that is stickied here on the site. Reading through all of that info helped me in visualizing how this stuff works.
John