Maximizing MPG on Long Uphill Grades

Not much.
1)If there's a downhill slope prior to the uphill grade and traffic isn't an issue you can try to glide/accelerate on the downhill and utilize that momentum to get you part way up the uphill section. I do this quite a lot on the hills in my area and am convinced it makes a big difference over time.

2) Turn OFF the cruise control before you start the uphill or start accelerating slowly before the cruise kicks in. As you're aware there's a delay of 1-2mph before CC kicks in and when it does it accelerates quite aggressively to try to get back up to speed. If you can maintain the base speed at a lower fuel burn rate that will help a little.

3) Lower your speed as much as reasonable and even allow the car to lose speed as you climb...again, traffic conditions permitting.

My scenario....I glide/hyperstealth down a hill as I approach an uphill section. Maintaining a very gentle acceleration on the flat before the uphill to maintain speed I slowly let the speed bleed off as I go up the rise. Sometimes I can get over the smaller hills without applying significant ICE power, sometimes on a tall steep hill it just gets me 10% of the way up...but at least I wasn't having to apply full ICE power from the base of the hill to maintain speed. Then, traffic permitting, I let ~5mph bleed off as I approach the summit and then regain the speed slowly as I crest the hill and begin the next downhill section...

This is going to have a subtle effect, but I think, if you track such, you'll notice an improvement in mpg of 2-4mpg over the next few tanks if you can do this approach.

 

I didn't really mention my speeds here, perhaps I should.
I allow my momentum to pick up as much as possible. On 55mph roads that sometimes means speeds of 80+mph by the time I hit the bottom of the hill (and that's using NO GAS power)! If you do not feel safe with that or there are other people on the road or many places where cars could enter PLEASE use your head and take safety into consideration first. I'd say that most of the time my speeds peak at 65-70mph on those 55mph roads and I let it blead off to around 45-50mph, but these are on rural roads in SW Missouri. On the highway/interstate I do allow momentum to pick up, but never let my speed drop below the limit (70mph on the freeway and 60mph on the hwys I usually drive).

And yes, I think conservative use of the AC (78-80 degrees F on auto AC setting) with windows up is a bettery, more fuel efficient and more comfortable way to drive, esp. on the highway.

 

<div class='quotetop'>QUOTE(mastergunnera8 @ Aug 2 2006, 09:38 AM) [snapback]296253[/snapback]</div>

You can do that, but there's really not much point and the savings are negligible if any. The Prius auto-AC system will actually decrease the output of the AC during times of high demand, like acceleration. It doesn't turn it off completely to avoid the cabin warming up which would necessitate a higher AC output to cool it off again...as would occur if you turn it off completely.

I used to do that too, but am convinced the benefit isn't there FE wise. That said, I DO think you can get a power boost by turning it off if you need it for a long steep climb.

 

<div class='quotetop'>QUOTE(Rand Reed @ Aug 2 2006, 09:56 AM) [snapback]296264[/snapback]</div>

Search Dead banding or dead-banding on PC and you'll find tons of info. Basicly you just feather the gas pedal until all but the yellow arrows (ICE to wheels) disappear on the Energy display.

While this is definately the single most fuel efficient way to go, it's completely impractial in real-world driving. All but the gentlest slopes will cause dramatic loss of speed due to the very low power output of the ICE in this situation. One could try it, but I think you'll have more frustration than you want for a tiny gain in mpg.

 

<div class='quotetop'>QUOTE(darelldd @ Aug 2 2006, 10:29 AM) [snapback]296295[/snapback]</div>

To that end, I recently had my after-market AgV switch installed: Antigravity Vehicle. Works like a charm.

I hope you have found out that there's really not much you can do to maximize MPG on the long uphills. I would have expected to have learned some little nugget from Evan, but when he starts a reply with "not much" then I know it's not just me.

My personal favorite - today anyway - is to make sure that as long as the engine is running, there's some charge going to the battery. You might not always get this, when by adjusting pressure on the pedal, you might find that you can from time to time. The reason for this is that as long as the engine is going to be running, I might as well be getting something for it. Also, just because a lot of acceleration is required at the base of the hill doesn't mean that you have to maintain that pressure all the way up. I have a couple hills on my daily commute that are brutal when starting but I can let up slowly on the pedal while climbing and see that my speed is still increasing and my "instant mileage" is also going up.

I've tried just about every suggestion given above. And depending on the situation, the one you use will change from incline to incline. So like everything else, the best advice is to take notes on all the suggestions and add them to your "toolbox" to have when you need them.

 

BRILLIANT!!

Way to go!

 

The ICE definately doesn't turn off in neutral, it may be very quiet and low fuel burn, but it's not off.

As far as the hyperstealth, you needn't see the arrows completely disappear, you just need to see them switching back and forth with a trend toward slightly more regeneration.