Haven't tried it yet, but am curious...what happens to the battery system when going up very long grades. Driving over passes in Washington involves uphill grades for many miles. In watching the assist for my normal commute and driving up the I5 corridor, it looks like a very long grade would exhaust the IMA battery. What happens then? Anybody have experience pulling very long grades?

Thanks,

Will

Well, not an expert like maybe some other drivers who routinely drive in mountainous areas, but I *have* one time driven up from 1500 to 12000 feet in Arizona.

I ran my battery dry more than once. That means 3rd gear, 4000 RPMS to maintain decent speeds when climbing a decently steep grade. I had a fresh oil change to Synthetic Oil just the weekend prior, so the high RPMs did not hurt me, but it was kind of different.

I still got 48.8 for a 230 mile mountain day trip, so I was not too upset !!

Hi Kayakwill:

___Given most 3% and up + grades of length have a slow speed truck lane as well, drop her down into 2 or 3, slow down, and hang with the Big Rigs. Driving 55 + up a mountain in a hybrid is about the worst thing I can imagine doing to your little beauty. Get in the truck lane, gear down, keep your RPM’s up and stay off the pack is about the best advice I can give. I do have to mention that my experiences driving the mountains in the Insight is exactly 0 so take my post with more then your average grain of salt

___Billy6 has posted here in the past and lives in the Washington area. I know he has done a few drives back into Utah and has had some seriously great fuel economy while doing so. PM him and see if he can offer some tips as he is very helpful in the Insightcentral.net forums. Great guy as well …

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net

[quote=xcel]... keep your RPM’s up and stay off the pack is about the best advice I can give.

Thanks Wayne. I seem to have trouble staying off the battery, even when gearing down on steeper hills. I'll just have to drive up to Mt. St. Helens one evening to see what I can do.

-Will

Hi Kayakwill:



___You can read about the rest of that adventure at the following …

MDX at the top of the world???

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net

Wayne,

I read the "Rest of the Story" and was curious. How much gas did you end up putting in?

Billy

Hi Billyt1963:

___You can start by reading this thread --> Third and Fourth post down entitled “You aren’t going to believe this!”. As for the rest of the thread, it dives right into the sewer given those that don’t know anything about hypermiling have to say this is impossible … I can do much better in that monster today as the end of the thread pics show

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net

I read your trip log. I wasn't sure how big the tank was on the MDX, so I went and looked and if I had been patient I would not have had to.

Congratulations on some great mileage. As I get better with the HCH maybe I can get respectable mileage in our Ody.

Billy

I just got back from a 2000-mile round trip that took me along I-40 from Oklahoma City to Phoenix. Along the way one passes the Continental Divide, and we additionally took some mountain roads with inclines/declines of up to 7%.

I learned a lot about my car on this trip (being that I only had 4000 miles on it when I left, the learning curve is still pretty vertical).

Assume you start at the bottom of a hill with a fully charged battery. Initially, the IMA will provide assist at very low power settings, say for conversation, 2000 RPM. As the battery depletes, progressively more throttle is required to get the IMA to assist such that eventually you'll notice the IMA favors charging versus assist except at very open throttle settings. With a battery charge of 1/4, I noticed that 3500-4000 RPM was required to provide assist.

I hope that makes sense.

Incidentally, I had some excellent mileage from Albuquerque to Wichita. 600 miles on one tank, 52.5 mpg at the pump. 60-65mph, cruise used in the flatter areas. Light and variable winds.

I noticed a 5mpg falloff when the sun set and the temperatures dropped.

Jason


Jason

Jason,
Thanks for the details on your trip. Especially the IMA behavior on steep grades.
Any idea what kind of mileage you got driving the steep grades of the Continental Divide? lars-ss said he got 48 mpg for his mountain day trip.

Eric Powers

MHG Organizer - www.MadisonHybridGroup.com
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Madison, WI