I think many folks mistakenly think that spinning the ICE to provide resistance on a downhill is killing their FE. I didn't realize for a while that it was doing that with the fuel cut off. I saw the RPMs jumping to 3-4K sometimes, but the FE continues to climb while it does that. If you were to reset the MPG display before going down a long hill, you would see that ICE spinning doesn't hurt FE. It's just giving the motor something to push against since the battery is full and there's nowhere else to put the energy. Of course all that only applies if your speed stays under 40 (which mine almost always does if I'm in 'L').

Every time I learn something new, I love this vehicle more than the day before!

 

This is a (barely) two-lane county road. Speeds are around 25 mph anyway.

I get a quick burst of high mileage readings where it almost flattens out for a few feet. Not long enough to affect the average noticeably though.

 

Hi All.
Seems I only get on here once a week and have a lot of catching up to do.

#1 Hilly terrain is where I get my BEST.... BEST BY FAR fuel economy.

I've had several long ( so engine is warm ) hilly ( Ok, Rocky Mtn ) trips in the 55+ MPG range... round trip ( not just downhill ). SUSTAINED for 87 miles at a time... and speeds of 35-45 MPH. Windy, twisty, roads with 5-6% grade. Yes... uphill hurts, but still gives me 25-28 MPG. Then the downhill run is almost FREE! Yes!!!! Like 8 miles in EV at a time, followed by one mile with gas just to keep the engine "warm". ( I hate that! ) On gentle slopes ( 1% - 2% ) I have done pulse & glide with a success of 50 MPG.

#2 FYI (Wayne) Pikes Peak is windy twisty with slow speeds and many grades OVER 6% for short sections. Never done it in my Hybrid, but have been there several times. ( The train route has sections of like 35% !!!! ) Cog Rail Required if course!

#3 Higher altitude = less wind resistance... similar effect to drafting. 5,000 feet = 15% less wind drag = better FE. Pikes Peak = 40% less drag! ( Granted, few people make that commute every day... )

#4 For me, I start at the bottom, and end up at the bottom. So gas is used going uphill, when the engine is cooler, and the downhill is when the engine is already warm.

#5 I don't think the FEH is worse on hills ( percentage wise ) than other vehicles ( Prius incl.) and in fact, I think it is better.

#6. Flat, blanket statements hold little value. The more I learn, and the more I read these types of forums, it is not so much the car, as it is the driver. The car is half of the FE, the driver is the other half. The FEH may get lower numbers on your particular route, plain and simple.
A different driver may get only marginally better results on the same course. Come to my home turf, and probably see your numbers rise.

#7. The lowest Octane possible gives the highest FE possible. PERIOD. Higher Octane is only for HIGH COMPRESSION engines, like high performance sports cars, and race cars. The FEH is not a race car, and in fact, due to the Atkinson cycle, has especially LOW COMPRESSION by design.
The 85 Octane I use in the Rocky Mountain Region is partially responsible for my hypermiler status with very little effort, and even in winter with 15-20 minute trips. I can only dream what 80 Octane would do ( if available ) as I have no doubt with my lower oxygen at 5,000 feet and gentle acceleration I would still have no knock.

#8 My only tank BELOW 30 MPG was also my only Tank with 90 Octane 10% Ethanol gas purchased ( by mistake ) in Iowa. Coincidence?
It is scientific fact that Ethanol has less heat per gallon than gas.
But the 3% cheaper price net me a 10-12% loss in gas mileage. Hmm....

#9 It's true, there is not any more advantage to the Low gear method of slowing down, than just using light pressure on the brakes. With a little more practice, I have been just as successful getting the ICE to shut down at 40 MPH with the brake pedal in Drive, as not with "Low". It is personal preference. If cars are behind me, I use low, so not to freak them out with flashing brake lights. If it's clear behind me, I use the brake pedal to shut the ICE down at 40.

#10 You can quit guessing and testing. It is a FACT that both 2wd and AWD versions can go 0 - 40 MPH in EV mode. FACT. The 2wd has no advantage, ( other than about 200 fewer pounds ) and there is NO WAY to exceed 40 MPH. The car is engineered this way, on purpose, and it is a hard coded limit. There is no technique to exceed 40 MPH in EV short of turning the key off, which can damage your car if you do this over 40 MPH. 41 MPH is NOT POSSIBLE. Maybe I'm splitting hairs, but reports of 41 MPH or 42 MPH in Electric only Mode are due to people mis-reading the analog speedometer. You are going 40 MPH when the needle fully passes, and totally clears the 40 MPH "line"... which to some, looks like 41 or 42 MPH. It is totally possible many people are going 1-2 MPH slower than they think ( probably a good thing ).

Cheers,

-John
(gpsman1 )
36.7 MPG for 13,600 miles ( Includes Winter )
39.9 MPG for last 3500 miles ( summer only )

 

HOW??

When our Escape is going up the mountain, mileage is in the low teens with
frequent excursions into the single digits. That is at 25 mph or so. I don't
know how you are getting almost double that!

Mine comes on after about 2 miles. The downhill still shows MAX most of the way, but it doesn't make up for the horrible mileage on the climb.

This shouldn't be all that surprising. Riding up that mountain on a bicycle takes 3 times as long and is about 10 times as much efffort as riding an equivalent distance on flat ground.

What surprises me is the results you are getting.

I couldn't even do that in the Prius.
Our Escape Hybrid on a 2% grade would be closer to 15 than 50.

Maybe 2000-2500 feet isn't high enough.

I start at the top, but with about 3 miles of relatively flat before I get to the road down, so the car has some time to warm up by then. I'm still mostly at MAX on the descent.

As I said, proportionately our Prius is worse. (A bigger percentage hit on the mileage when going uphill).

ALL California gas contains about 10% ethanol, and every tank I have burned has been below 30 MPG (though others have reported much better results).

It is distinctly perverse that the engine comes on when we're going downhill at
40.00001 MPH, though I'm not sure it really hurts the mileage much.

 

It doesn't hurt at all, and it keeps your motor/generator from self-destructing.

Your Prius does the same thing for the same reason :-)

 

Steve - I disagree. "gliding" downhill above 40 MPH with the ICE does use some gas, but not much... maybe in the 60 - 100 MPG range.

Gliding downhill at 39.99 MPH with the ICE off uses ZERO gas.

How do I get 50 MPG in the Mountains?

Say I go 50 miles uphill, and average, 25 MPG. This = 2 gallons used.

Then, I go those 50 miles downhill, almost all in EV, by keeping it under 40 MPH the whole time. Now, I've gone 100 miles round-trip on those same 2 gallons.

100 miles from 2 gallons = 50 MPG.

Actually, in my real experiment, I went 87 miles R/T from 1.61 gallons, which is closer to 55 MPG.

I have done this numerous times, and have had two other people in AWD models ( mine is 2wd ) get about 48 MPG on the same route.

Maybe it's a combination of road conditions, weather, thin air, and actual gas mixture ( mine is 85 octane and all gas in summer, 10% ethanol in winter... ethanol gets fewer MPG... )

In stop and go city, I can run in EV for up to 78% of the TIME ( 46 minutes per hour ) granted, few miles go by, like 20 per hour in the city... but also, this keeps me over a 50 MPH average.

Flat highway driving is the worst case. About 35 MPG at 65 MPH.
This drops off dramatically above 65.
Like 31 MPG at 70, 28 MPG at 75, and 24 MPG at 85.

Those people who get 24 MPG must go fast all the time!

 

That is the part I don't understand. How do you get 25 MPG going UP the mountain?
We drop into the single-digits and teens on the inclines. Even at 25 mph.

 

I think he was making up an example.

There are very few non-trivial inclines one can get 25 MPG climbing...

 

Tow Truck.

 

What I'm finding out about my FEH is you can adjust your driving skills for any terrain and still get super MPG. If you make no adjustments and just drive, you will get what you expect. Thats not good enough for people like GPSMAN1, ecel and others including myself.

When to drive, how to drive and where to drive to get to my destination is very important and I think it is the reason I can understand GPSMAN's numbers. My thinking is that the FEH can get over 60mpg. Its all these challenges in driving conditions that brings your averages down. Learn to overcome these driving conditions and you can average over 40mpg with very little problems.

I don't have the mountains but I have some long steep bridges. Example, when traffic permits, I stay in EV at 35mph and cancel the cruise at the beginning of the bridge. I coast to about 25mph and apply pedal at that speed and maintain EV almost to the top when the ICE starts. I go back to EV with the Low Gear Advantage recharging the battery most of the way down keeping under 40mph. Then put it back in drive to pick back up to 40mph for a long coast after the bridge mantaining 60mpg + during this challenge.

Use the Fake shift on long inclines as needed and use EV at slow speeds whenever posible. The ride down will be easier and blast your MPG.

Gary