I thought that I’d share what I’ve learned about the HiHy and how to maximize FE, at least in my environment. Before I got my HiHy, I was reading and absorbing as much as I could here at GreenHybrid. In reading the advice provided on this site, much is standard stuff that hybrids or non-hybrids can do in general to improve FE. These include things like anticipating stops and starting to coast earlier, being gentle on the accelerator etc. When we get to the hybrid-specific advice, I pay much more attention to suggestions for the Prius (same hybrid system) and the FEH (similar size/weight issues and similar hybrid system) than to Honda-related suggestions. We simply don’t have an “assist” bar or “eco” mode so those suggestions are meaningless for the HiHy.



While I can’t claim “hypermiler” status, I *am* in the upper 1/3 of posters in the RMDB and I have the second highest total mileage so my experience should count for something. I live in the foothills of Colorado, south-west of Denver at an elevation of 8500 ft and commute daily “down the hill” to the Denver metro area so I have a daily gain/loss of approx 3000 ft. Even while in the metro area, I rarely encounter flat roads so take that into consideration as well when comparing to your own situation. I have tried PnG in a very limited manner, I believe that this works better in the flats than in the rolling hills that I tend to travel. Also, the “pure” PnG suggests that the Glide portion be truly “no energy to/from the wheels” … I have never been able to achieve this feat unless on a downhill slope. My energy monitor shifts quickly from sending energy from the wheels to the battery to the reverse with only a momentary pause of no energy flow no matter how careful I am. I suspect that much of this relates to the size and weight of the HiHy so I don’t worry about that much, the slight regen when coasting doesn’t seem to be of much concern to me.



My first piece of advice is to coast as much as possible. This car coasts extremely well in my opinion and I am sometimes amazed at how far I can go with my foot firmly on the floor, not touching either pedal.



Next – when accelerating from a stop, I have found it virtually impossible to get to a cruising speed (20-30 mph) without use of the ICE. If you are in true “creep and stop” traffic, then EV is very possible, even when going uphill. If, however, you need to reach a reasonable cruising speed, I say to do so in a smooth fashion – not too slow but not a jackrabbit start either. As soon as you reach the desired speed, however, take your foot totally off the gas pedal to shut down the ICE and gradually reapply with just enough pressure to maintain the desired speed. This often allows you to get back into EV mode if you are on flat roads or downslopes and on uphill slopes, it can reduce the energy being used.



When accelerating, pay attention to the energy gauge that replaces the tach – you want to keep the energy usage low, as close to the broken area as possible. When cruising, if your energy usage is in the broken area, you should be seeing 60mph+ or close to it on the instantaneous MPG graph even if you happen to be using some ICE. When your usage hits about 50Kw or so, your FE has dropped significantly so pay attention to where that gauge is sitting while driving.



The FEH forums have some good advice. The “Low Gear Advantage” thread is very interesting however I’ve never been in the situation of wanting to use EV but having too little battery charge to do so due to the hills I travel. My battery gets charged enough just coasting. I *do* use B when going down steep slopes or long slopes to keep from gaining too much speed. If you live in a flat area, the advice re the use of "Low Gear" (our B) may be useful to you. What I do after accelerating is what I believe is referred to on the FEH forum as a “fake-shift” – it works well for me.



I know that this is a long post but I hope it helps some who have been struggling with their FE.

 

Thanks for the info, as a prospective buyer of my first hybrid I found this article very informative!

One question, point: I was reading on this site that using the "b" should be avoided since it doesn't allow the ICE to stop (the ICE is used as the engine break). If this is true then I don't think using "B" is that fuel efficient (maybe if the ICE runs without using any gas). I suspect that coasting using light break pressure (reg. breaking) would work better.

That said, I've never even been in a hybrid so this is just me taking a wild stab. Will be interesting so see what people think.

 

I went to that site and found:
So, no fuel is used when you invoke "B" (unless you're in B and press on the gas pedal)

 

You seem to be correct. This is a cool feature for hilly rides as it turns the engine but without gasoline... pretty clever no? Maybe a way to avoid overcharging the batteries?

 

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We just filled up our HiHy for the third time. We decided to try 89 octane, since we calculated that it would only need to improve mileage by 1.5 mpg to be cost effective. On the first hour of the new tank, mpg is up 2.5!

 

For the first few thousand miles on my HH, I was having a hard time getting a good technique for when traffic was light on the highway on my commute to/from work. My mpg is great when the traffic is heavy, but dips a lot when there's no traffic and I can go the speed limit (65-70).

From my driveway to the hiway, I have about 2.25 miles of neighborhood streets with less flat and more gentle grades/hills. Next, I have about ten miles of hiway, half flat, half gentle grades with a few hills (one long hill going up to work, but a great coast coming home). Then, off the hiway again for about another 2 miles on access road/side streets to the office. I have two interchanges, and in San Antonio, that mean going through two asinine traffic lights.

I can get into the dead band coast, pretty easily now, but it was tough and required lots of practice. I personally don't notice any difference between coasting with my foot off of the pedal vs. a dead band coast. I cannot perceive any resistance when the indicator shows battery regen, or a reduction in resistance when I stop regen and hit the dead band. Maybe the HH is too heavy to make this noticeable. I haven't found a good road yet (or maybe I really haven't looked hard enough) that is flat to test the difference with some good data, to see if the coast will be longer in the dead band with the same speed.

I have discovered a technique that seems to help with highway speeds. I know many have noticed the effectiveness of using cruise control, but my experience on my gently rolling highways in San Antonio has only resulted in a best mpg of about 25-27 using CC. I have found I can do better than the CC by using the instantaneous mpg meter as a feedback mechanism. Use the dash meter, viewed with your peripheral vision so your eyes don't leave the road too much. This technique seems to require a minimum speed of about 45 mph. Wayne is not going to like it because it uses the battery/elec motor, but my hiway elevations and traffic conditions just don't permit effective p&g because the coasts bleed down to fast because of repeated uphill grades.

Here's what I do on the hiway when the traffic is moving smoothly at the speed limit:
Get up to speed as you normally would on the hiway, let's say 60 mph. Instead of p&g, which in this situation will really annoy other drivers in smoothly moving traffic, I ease off the gas pedal very slowly until I see the mpg meter hit somewhere between 40 and 60, then I freeze the pedal. In this condition, the eCVT seems to find a taller gear, and the elec motor kicks in to assist. Holding this, the elec motor will come on and off, I guess depending on whatever, I don't know. This state bleeds off speed much more slowly than a p&g, even with gentle uphill grades. I can hit this state at 65 or 70 mph, and I can keep this state for several miles until my speed bleeds down to about 55. At this point, I very slowly depress the pedal until the mpg meter hits at or just below 20. In this state, i'm using the ICE, but the HH accelerates very gradually without tanking my avg mpg. Once I'm back up to 65 mph, repeat. Using this technique, I've been able to keep my mpg above 30 so far for my current tank (I'm down to about 1/4 tank having travelled about 370 miles at 31.0 mpg avg). If I can keep this up, this will be my first 30+ tank, on the computer anyway. We'll see what my manual calc says when I fill up.

 

Ok, I don't know what the highlander is rated for BUT using HIGHER octane gas then what a car is rater for will NOT i repeat NOT help your gas milage and NOT I repeat NOT give you more horse power. Higher Octane is used for engines that require higher compression, this way they can be designed to run at higher compression generating more horsepower but it will NOT save gas. Higher octance gas actually has less energy in it (the octane rating specifies at what compression it will explode and not energy level!).

So don't use higher octane gas, it will not help you, it will pollute more and cost you more money.

 

Lots of capital letters doesn't make your argument any more forceful or any more correct. The Highlander owner's manual states "For improved vehicle performance, the use of premium unleaded gasoline with an Octane Rating of 91 (Research Octane Number 96) or higher is recommended." It certainly does save us money, since the gas mileage has improved more than enough to recoup the extra 10 cents per gallon for 89 octane (haven't tried 91 yet, since we want to experiment with the 89 for a few tanks). And I never said it gave us more horsepower, nor did I say anything about energy. It is simply more efficient than 87 octane in our experience. Using higher octane than your engine is designed for doesn't give any benefit, and can cause excess emissions. However, the Highlander is designed for the higher octane, and therefore gets improved performance (as we've seen with ours in the real world).

 

Ok,

If the engine is rated for 91 then I do believe it will generate better gas milage, my point was merly don't run on higher octane then what your car is listed for (many people run 91 or engines listed for 87 and that will not make a difference).

Modern engines when they detect lower octane gasoline will "retard" the timing as to avoid pinging. I could see how this retardation could go over board and would actually make it use more gasoline.

it will be interesting to see what happens if/when you try 91. I suspect 89 could be the best compromise.