ooops



I also put her in 'cruise control' on the highway at 63mph instead of trying to 'pulse and glide' myself. I get better mileage letting the car do what it was designed to do itself.



cheers

I bought it for the epa MPG. I am pleased to say that I'm happy with this vehicle even when my MPG is 20. I replaced my 2003 ML500 with this car. I can tell you that the acceleration is similar, handling is similar, the finish is well um ... did I mention I seat seven just as well and have better "trunk" space, and I get double plus good gas mileage.
My mileage is best on the highway when I just leave my foot steady on the gas (up to 32mpg). I say drive normal and let the electrics do their thing.

Shiloh,

You have an impressive FE driving record, which speaks for itself. Perhaps you can share your driving style/techniques/conditions that account for your stats instead of having newbies like myself speculate.

It would be great to for others with HiHy FE > 26 mpg to share their experiences, techniques, etc so that they can help others with lesser FEs decide whether or not they want to attempt to adopt those techniques and driving styles depending on what's most compatible with their lifestyles and values.

For me, I'm still struggling to find that tradeoff that best matches what I'm satisfied with in terms of FE and sufficient performance usage (the fun factor). For example, it would be great to know if folks that are getting an overall lifetime >27 mpg are pretty much always <65 mph on the highways and <45 mph on the regular streets and expressways. That way folks like myself can better understand the "cost" for getting such great FE and determine a nice compromise based on facts from other folks' experience instead of potentially getting frustrated or rationalizing away the potential savings.

-Han-

Han,
I hate to say it but, if you are a conscious driver (which you are), fuel efficiency has more to do with where and how long your trip is as opposed to how you drive.
The epa city mileage is erroneously subjective. Consumer reports comes closer to reality. What we need to see is 3 mileage ratings. Something like stop and go city limits (19mpg for me), 20-45 city and highway cruising (27-29mpg), and pure highway 55-70 (24-32).
Acceleration kills FE. You can't help it stop sign after stop sign. Even if you stay in EV mode, eventually you use up your charge and the ICE has to make up the difference, which is less efficient than using the ICE alone. (I look forward to a plug in upgrade, it will sure help with taking the kids to school and back.)
If you can avoid large changes in speed, your FE will be superb. Thus the theory behind pulse and glide....

In reply to hsolo142 I really haven't done anything "extreme" in getting the mileage I'm getting. I've always been a fairly conservative driver- usually driving within 10mph of the speed limit on the highway and probably within 5 on surface streets.

I am "blessed" with a 37mile one way commute that takes me just about an hour to drive. I live in the foothills outside of Denver. My daily commute starts by heading uphill in the neighborhood on dirt roads for about a mile. I'm then on paved roads, mostly uphill but some downhill for another couple of miles before I hit the main highway. The highway down into town is limited access but not true freeway. Speed limit is mostly 55mph with some 45 and 65 thrown in. They've recently started construcition for the 2 miles closest to my entrance to the highway so speed limit there is down to 40. I love the downhill, I mostly just coast with my foot on the floor. Anyone who lives in mountains knows, however, that it's not pure uphill or downhill - there are pockets of each both directions. After 16 miles downhill, I then need to get across the metro area. Long before I got my hybrid, I decided that it was much easier on my mood to take the surface streets (almost a straight shot) enduring traffic lights than to try the freeway that circles around since it seemed to me that almost daily there would be significant traffic tie-ups on the freeway.

The surface street option actually starts with approximately 5 more miles of freeway type driving, starting with 65mph then dropping to 55. Once the signals start, speed limits are in the 35-45 range although traffic tends to flow at about 45. I hit a few stop signs as I wind my way through a couple of neighborhoods to get to my office. I pay attention to traffic and don't speed to red lights but don't try much beyond that.

On my way home, I actually revise my route across town and take small 2 lane roads with lots of stop signs and a fairly consistent 35mph speed limit. For most of the stop signs, I get up to speed then mostly coast to the next stop sign. If I have several cars behind me, I don't do that as they get a bit impatient. For some reason, the traffic on the "main drag" seems heavier or maybe I'm just less in the mood for it on the way home. The smaller streets keep me calmer and only add about 5-10 additional minutes to my entire commute. The uphill on my way home, with speed limits of 55-65 are the killer. My instantaneous FE tends to be in the low teens for those segments. I don't baby the car uphill as I found that even dropping to 35 mph didn't improve the FE much at all. Unfortunately, the uphill portions rarely afford me the option of having picked up speed to carry me partway uphill so I just go with the flow there.

I don't have any aggressive freeway driving to contend with and even my stop and go portions aren't gridlock.

I guess my only advice would be to stay calm - don't drive aggressively but don't drive like a granny either. If I'm at speeds below 40mph, I try to use the EV but I don't obsess over it. Above 40mph, try to keep the power consumption meter as low as possible.

gang

i found that i get lousy mileage cause we drive it 3 times a week to the store which is a mile away. We have 650 miles on it after 2 months , mainly due to 3 long trips of 170 miles round trip .

I agree with what everyone is saying, except , how are we supposed to 'pulse and glide' when we are constantly starting and stopping? Like every block.

If we get the converter warmed up , it helps, but if we drive long enough without having to stop -then the mileage goes up anyways as its being driven smoothly without accelleration .



Great post you guys.

I got my first ever 27.8 mpg tank! I covered 369.2 miles with 13.3 gallons. (I had a 30 mpg 1/4 tank before, but that was a fluke.) Bizarre, I'm not quite sure what bag of factors contributed the most to these numbers: 1st attempt at pulse then glide (shifting to neutral), ~5-10 degrees hotter, filled the tank at the slower setting, a lot of errands on local streets... Another bizarre first, the only tank out of the 15 recorded where the EM measured a FE lower (only ~1%) than the manual calculation. I also had the A/C on quite a bit during the weekends and several times during the weekdays. Strange.

Of all the factors that could be contributing to this FE, I think the pulse and glide (by shifting to neutral) was the most significantly different behavior. I had filled several tanks before at the slower setting. The weather has been getting pretty hot for the last 2 tanks. I also had lots of errands for the last two tanks as well...

I guess proof will bear itself out in time. I'll try to continue to pulse and glide by neutral for this next tank and see if I can reproduce this FE number... Even I'm skeptical!

hey han


congrats on the excellent mpg.

I am -as you know- dubious about driving in neutral, even though i do it all the time in my standard base model ford escort.

what is the diff about driving in neutral? Does that make you 'coast' without using battery power?

cheers

Tom,

Yes, driving in neutral allows you to coast without using any battery power. That battery power is then conserved for stop-and-go acceleration. Coasting or "gliding" in neutral is basically another method for performing "pulse 'n' glide". If you don't have a hybrid car, it's the only method available for performing pulse 'n' glide.

In the spirit of having my cake and eating it too, shifting to neutral (where appropriate) allows me to perform some "pulse 'n' glide" without much work. Lazy way is good for me...

The concepts behind pulse 'n' glide is fairly straightforward, even if the execution of it is not. However, I haven't found these concepts clearly stated in the various FAQs and comments about pulse 'n' glide on this website. 1. Minimize the usage of the Internal Combustion Engine (ICE). (That's pretty obvious) 2. For hybrid cars, when the is ICE on, maximize the percentage of energy used to power the front wheels.

So, the ideal pulse 'n' glide is to first accelerate such that most if not all of the ICE energy is powering the front wheels. I find this difficult to do in the HiHy without sacrificing acceptable acceleration. I always notice that some portion of the ICE energy goes back to the electric motor to recharging the batteries. Fretting about what acceleration avoids the battery recharge is too much work for me (i.e. another example of lazy-man way). When you get to your ideal cruising speed, you're supposed to lightly let off the accelerator and push down again until you see no energy flows (neither power nor regenerative) in your Energy Monitor. This is the "glide" mode. Again, I find this very difficult to do unless I'm traveling about 35 mph or slower. Even then it's a real pain in the butt. Instead, I do the equivalent, which is shifting the neutral. When you do that, by definition there are no energy flows... you're gliding.

Where you do want to NOT shift in neutral is when you want to slow down and convert that to regenerative energy. So, what I try to do is only shift occasionally into neutral when there is a section of the road or highway where I can simply coast and afford to slowly slow down. However, if I notice a red light ahead or traffic ahead, then I shift back to drive and notice the additional drag due to regenerative "braking" recharging the battery. If I don't do that and simply brake while the HiHy is in neutral none of that braking goes to regenerative energy.

The alternative to this glide mode is to cruise by letting off the accelerator and then pushing slightly back down again until the only energy flow is from the battery to the electric motor powering the wheels. Here you're not using any ICE. However, you are using electric power. This electric power is then spent maintaining a cruising speed instead of helping out powering the HiHy during acceleration (especially stop-and-go) when the ICE power is most inefficient.

I'm not convinced yet if this glide in neutral is having a significant impact on my FE. Especially since I only do it occasionally. I'll try it again for this tank and see if I can get close to reproducing that ~27 mpg FE number. We'll see...

ok

It seems practical to try it on a sloping downhill highway or pysedo highway where risk is minimal. I just dont want to be caught unaware and have to jam it back into drive and risk damaging the vehicle. So city or congested traffic is out for me.

cheers