chromedome

After much too long reading about Toyota's hybrid system design, I decided to try some new tricks on my usual commute. It's a 70 km round trip, 50% highway and 50% city streets, and I got 4.7 l/100 km or about 50 mpg.

Highways

I use cruise control set to about 70 mph when there's light traffic. The terrain is all flat here anyway. The computer juggles ICE/electric transitions better than me and it gives me time to listen to... Old Smashing Pumpkins

When traffic slows down, I pulse to 2000+ rpm on ICE and glide on the battery. I rarely use regen on highways. Above 50 mph, the engine freewheels at 1000 rpm without using any fuel; below 50 mph, the engine drops to 0 rpm. You can see this if you enable the tach in all drive modes.

City streets

I do pulse and glide here too, 2000+ rpm on ICE and gliding on battery. I don't let my speed drop down too low so I don't annoy other drivers. If traffic is dense but flowing smoothly, I just maintain constant speed using cruise control.

As for traffic lights, I look far ahead and coast/regen accordingly. I don't understand why some drivers like to accelerate towards a red light and then brake hard.

Rural roads

I've gotten an insane 65 mpg when going through rural roads in the foothills where speeds are limited to 40-50 mph. Surprisingly I got better results with cruise control on instead of accelerating downhill and slowly losing speed going uphill.

Issues

I can't find any BSFC (brake specific fuel consumption) figures for the ES300h or the current Camry Hybrid, only for the 2007 Camry Hybrid. That would give the rpm range which has the lowest fuel consumption for the most power, specifically 230 g/kWh. I'm using 2000 rpm as my acceleration target point based on the old Camry data.

I can't get Prius-style warp stealth to work: in the Prius, even above 60 mph, it's possible to let the engine coast at 1000 rpm and then use the motor to glide, with the energy display showing power going from battery to motor. In this car, touching the pedal above 60 mph makes the engine wake up. Ironically it's only with cruise control on that I've seen the car glide on battery power.

I'm really happy that such a big car can return high mpg with some careful driving.

TechNut

Well done on your mileage. The best we have been able to achieve in the first four months of ownership is 40.9 mpg calculated. Our commute is about 25 miles on city streets, with the fastest stretch at 45 mph - and the occasional jump on a short interstate trip to a neighboring town. We too have found that the car can show the best mileage using the cruise control, particularly in the speed ranges you referenced, but it is extremely rare that the surrounding traffic flow will allow it.

I would urge you to be careful that your driving style isn't so dedicated to achieving high mileage that you become an irritant to other drivers around you. This happened with many Prius owners, to the point it gave the car a bad name when in reality it was really just some poorly behaving drivers (i.e. discourteous) that were trying to suck every last ounce of mileage from their cars because they were in some odd competition. I'm just suggesting we don't want to give the ES 300H that same stigma. I am always careful to ensure any efforts to maximize my mileage don't occur at the expense of other drivers. No offense intended and I don't mean to sound like I am lecturing, rather sharing experiences I had during my years of Prius ownership.

I agree, the mileage these cars return for their size is really remarkable. I also love the range this car achieves between refueling. Overall, we couldn't be more delighted.

Arty101

Chrome- I'm impressed with your mpg. I've got to learn more on how that pulse/glide technique works. I've gotten no better than 40.0 mpg calculated with conservative driving, trying to use EV in the city, cruise for freeways, and anticipating stop and go traffic without using ICE.

Then again, I don't drive like Prius drivers that pissed off others. I try to keep up with traffic.

chromedome

Nope, I didn't and have no intention of doing the stereotypical Prius hypermiler thing. I'm always keeping up with traffic flow and I put safety first... Traffic here is pure insanity compared to North America

Pulse and glide involves using ICE power to go slightly beyond target speed, then gliding on the traction motor (without regen) until you drop below a certain speed, then doing it all over again. I only use it if there's not much traffic and I don't have a large speed delta to avoid annoying everyone else.

The funny thing is that you want to avoid manually setting EV mode because that battery power could be used to maintain cruising speed. The engine is most efficient at accelerating and high speed driving, the electric motors are better for low and medium speed cruising.

I use a custom setting to show the tach in all modes and I have the center display set to energy flow. I'm usually in Eco mode, it's easier to modulate the throttle to avoid regen.

Most of the time, I accelerate at 2000-2200 rpm to get up to target speed and then I use cruise control. That rpm range is supposed to have the lowest fuel consumption for the most power. On level ground, the cruise control computer does a good job of switching between ICE and EV modes and maximizing efficiency. It's not so good in hilly terrain because it wastes gas accelerating uphill when it's better to lose some speed going up.

zes

Chromedome you the man! I can never get more than 42mpg no matter how hard I try. I must try harder! BTW how do you set the tach to appear in all modes? I don't recall a setting for that.

Arty101

The tach mode is one of the 9 customizable displays with the Disp. button on the steering wheel. I have mine already set to that, and the center display also set to show energy flow so I don't run down the traction battery.

I only use the EV mode with gentle acceleration and then to maintain speed under 35mph. Anything more aggresive or over 35mph would trigger the ICE. I thought I was doing pulse/glide technique correctly, but there must be something else I'm not doing right.

chromedome

Are you manually setting EV mode with the EV button? I rarely use that because I don't have enough charge for it. It's also not very efficient, that battery charge could be used to maintain speed instead of accelerating the car.

It's a bit counterintuitive but you want to minimize battery usage. I always accelerate on ICE power at 2000+ rpm, then go off the throttle before feathering it to glide on the traction motor. Regen should also be avoided because of mechanical-electrical-mechanical conversion losses. It's better to just maintain momentum on battery.

NickTee

How about if you drive like a normal person who isn't trying to hypermile?

chromedome

36-40 mpg I'd guess...

Is there a problem with me trying to hypermile?

Arty101

Nope, I don't use the EV button. I just tried not to accelerate too quickly to set off the ICE, and use the traction battery to maintain speed when under 35 mph. I see it being counterintuitive to use the battery for acceleration, so I'll change that habit right off. But the traction battery needs to recharge even to maintain momentum so there's no avoiding regen, right? I just try not to invoke the ICE for the regen especially at stop lights when the battery is down to 2 bars.

chromedome

Yup, I use regen when coasting to red lights, but I usually glide on battery on straight, flat stretches. The downside is that charge runs down faster and sometimes the ICE needs to run when idling to recharge the battery. Overall it's still a more efficient way of driving.

I used to avoid triggering the ICE on acceleration but now I do the opposite.

Arty101

Well you must be doing something right. I'll adjust my acceleration accordingly. Thanks for the tips.

Riles

Great job! I have an annoying commute right now- 60 miles each way, most of it on a very high speed highway (54 miles on the New Jersey Turnpike, 6 miles on surface streets). I found that if I keep my speed limited to around 70mph with cruise control, my mileage is close to 40mpg for the whole trip. Unfortunately, I usually want to be home faster in the evening and I'm chronically "late" to work, so I tend to drive closer to 80mph and the mileage drops significantly- into 36mpg territory.

If ever I happen to leave early for work and there are no other cars around, I will try to get a good stretch of pulse and glide going to see if I can get anywhere near your (great!) results.

PirelliRC

hey i was in China the other day, i saw chrome pulsing by.
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NickTee

As long as you stay out of the way and don't cause congestion by being in the wrong lane, no. Did I say there was a problem with you hypermiling, or are you simply being defensive?
I was simply curious, since the hypermiling driving style is not that of a normal person.