Hi Andrew@vr66.com

___As Tbaleno and I both commute into and out of the Chicago area daily, the temps and winds over the past 2 weeks have been absolutely wicked for those attempting to figure out what a brand new hybrid is actually worth in the FE department. Unfortunately, our 10-day forecast does not bode well for you either with the high over the next 10 appearing today. With the Bears kicking the snot out of the Panthers, you are probably better off staying in and watching the game but if you were to do any FE testing whatsoever in our climate this time of year, right now would be the time … I would suggest pressing up your tires to at least 44 #’s all around to start as I can bet your Honda dealership saddled you with 30 - 32 # mush right off the lot Given your location, I have the feeling you are getting hammered from deep inner city driving as this is not an IMA based hybrid’s forte’ without some well placed tricks thrown at a commute like that?

___Another item not relating to your HCH-II directly … Where in the Chicago area do you live again exactly (Wrigleyville possibly?) and would you be interested in meeting Tom and I for a quick get together to do a small shakedown of your HCH-II? I can give you a short clinic on hypermiling in my non-hybrid Accord as well as your HCH-II from what NASAgineer has given me besides the rest of the techniques we use … I am sure you would like to try out Tom’s HCH-I w/ CVT for comparisons sake also? And please consider joining some our Wisconsin hybrid owning neighbors at the Madison Hybrid Group meet in late January. The MHG meets are always good for a tip or two as well as meeting and speaking with other hybrid automobile owners The January meet will include a presentation by a local Honda dealerships presentation on the HCH-II which may add knowledge that you may not have seen or understood before?

___Good Luck

___Wayne R. Gerdes

 

BTW if it is any consolation EVERYONE is getting sucky MPG this time of the year where it is cold.

Those EPA=17 MPG SUVs are getting 10 MPG right now.

 

My hat is off to all of you in the Great White North who are really working their vehicles to their full potential.

 

Great. I never used cruise control but driving regularly even at 60 or 70 mph I seem to often get worse FE than at 80 mph, oddly, though 50 mph is highest. So I'd be interested in hearing what your car gets with cruise control. By the way, rather than merely measure in the same direction, a much better test is to measure in both directions on the same road. So you can drive 20 miles one way, record, turn around, reset trip meter, then drive 20 miles the other way.

Haha, maybe, but your posts have been pretty scientific, which is appreciated.

 

Good idea. I'll do 60 both ways on Monday, 70 on Tuesday, and 80 on Wednesday. Hopefully traffic will cooperate!

 

Keep track of temperature and winds too. Those can make a big difference.

 

Recording round trips minimizes the effects of wind assuming it remains consistent during that time, but temperature matters. However San Jose should be pretty warm.

 

Recording round trips reduces the effect of wind on your calculated MPG but doesn;t eliminate it.

Let's say you drive 60 MPH with a 20 MPH head wind one way and a 20 MPH tail wind the other way. The increased drag from a 20 MPH head wind is greater than the reduced drag with a 20 MPH tail wind. So the net effect of any wind, even on a round trip, is to make your FE worse.

 

Yeah, you're right, since it increases exponentially. My bad.

 

Here is a formula for drag taken from a NASA web page.

D = Cf x A x r x V^2/2

Where:

D = drag
Cf = coeff of friction
A = area
r = air density
V = velocity

Note that the velocity is squared. Also, your true speed is the speedometer +/- any head winds, tail winds, cross wind vectors, etc. If you have a 20mph head wind and you are going 70mph, then your true air speed is 90mph. (maybe a pitot tube makes more sense for hybrids ). Makes a difference when you square 90 vs 70 in the formula.. I will admit that 20% is a lot but if you do the math, the drag doubles when going 90mph vs 70mph given that all other factors remain the same.