Traveler1

We know MPG equal to
[Distance] / [Gas consumption]

And also it equal to
[Engine Efficiency(MPG)] / [Engine usage ratio by distance]
which:
Engine Efficiency(MPG) : It is the efficiency when ICE is on.
Engine usage ratio by distance: It is the distance ratio as [ICE on] / [Total].
You can observe them roughly.
As for the Engine Efficiency, you can monitor it through Instant MPG.
As for Engine usage ratio, you can control it through gas pedalling and the power monitor (dark green zone).

So, to get the better MPG,
1. on the downtown or residential area, run without ICE power to get better Engine usage ratio.
2. on the highway (MPH=50-), ICE is generally on. so monitor and control to get better Instant MPG. To do so, [1]keep constant speed (= without needless acceleration) [2]leverage downhill - gravity accelerate the car so that ICE ECU stops fuel injection.

As for myself,
1. Engine Efficiency = 8-10 MPG, Engine usage % = 30% roughly.
2. Engine Efficiency = 25-30 MPG, Engine usage % = 95% average.
Running on uphill or accelerating, ICE efficiency = 10-15 MPG.
Running on downhill, ICE efficiency = 50-100 MPG.

Another incident is idling.
1. Warming up the ICE. In winter it cost much more.
2. Charging. If the battery level comes around bottom, idle until half level.
3. Air conditioning. Idle to warm coolant water.

Enjoy!

DunWkg

I'm confused by this. If I use the engine 95% of the time, MPG goes up? If I used the engine 30% of the time, MPG goes down. Shouldn't it be the other way around?

Per this extreme example: sitting idling, I'm getting 100% engine usage and zero MPG. Actually in the moment, it becomes gallons per mile. If I'm coasting downhill on battery, I'm getting 0% engine usage and infinite MPG at that moment (probably shows up as 90 MPG on the instantaneous gauge). From the moment I reset the average speed (MPH) and the average MPG on the mult-informational display until I push the button again and reset both averages, the car is analyzing all those moments, miles driven and fuel used passing through the number one injector (calculating total fuel used in all injectors) for MPG and the average speed, including standing, as stopped is a speed (zero miles per hour).

Like I said, I'm confused, but shouldn't more engine usage mean lower MPG? What time is it and where's the caffeine?

Traveler1

Sorry for my slow response.

As for case 2, it means "using the better, efficient zone of engine while running on highway", while 1st case means "save the ICE time".
I do not know how I can make control the Atkinson cycle direct. There is no description about it on the manuals. I assume it works when weaker ICE power is required such as:
1. running "flat to slightly down" speed on the flat road
2. running constant speed on the slight downhill
3. running as "free fall" on the downhill

I drive 60 MPH on highway, and I observe the Instant MPG on the case above as
1. 30-35 MPG
2. around 45 MPG
3. 90- MPG
(ICE is always on, but ECU makes saving fuel)

To make the situation, I control gas pedal to indicate power meter as:
1. top of dark green
2. middle of dark green
3. 0 (between ECO and Regeneration)

Keeping the state, total MPG will be improved on the highway.
As for myself, target MPG is 30.9 for Tokyo-Nagoya (200miles) round trip keeping around 60 MPH in December.

TampaOwner

my RX450 is only averaging 25 mpg . ive had it two weeks... thats with normal driving behavior...

Traveler1

Yours is better than mine. It was 22-23 MPG average when I've got it last December. Especially winter record is worse because ECU enforces ICE ON to warm catalyzers and engine itself. Once they are warmed up, then you can observe better record like spring or summer. Yet, you know ICE is OFF while running the best condition, it takes long time to reach the "better" state. I estimate it takes 10-20miles running in Tokyo (about 40F). So, the short round trip (ex. 5 miles ea) gives wrong record (18-20MPG). Instead, there is a merit. Because ICE is longer ON, the state of charge is better in winter, which I found this December. We can leverage this by using EV mode intentionally when starting at signal, etc.

DunWkg

Traveler, your last sentence is worth noting. I haven't put my 12 into Eco (or EV) mode yet. Been training it to drive "normally", my normal. Will begin Eco training soon. If training is even possible.

Looking a Goggle Earth, Tomei Expessway looks like an interesting road.

Traveler1

As for enforcing EV mode manually, I also use it in a parking lot. I can control throttle without using ICE in May to November. But in winter, ECU makes ICE ON not only at slow speed but also backing despite the state of charge is enough, before warming is completed.

As for the expressway, the landscape through Gotenba to Yui is fine (Mt. Fuji, and Yui sea shore looking over Izu peninsula).

TampaOwner

i discovered the Econo mode and that makes a huge difference.. i increased my average by 2mpg on ine 15 mile trip... i switched it to EV mode for the last two miles in my 25mph neighborhood... i made it 2 miles and the battery dropped to two bars... but it sure felt good to be cruising on battery only

Alpy64

Hi Guys (I'm from France)
your figures can be better if you put attention to your driving behaviour.

To save fuel and limit emissions, anticipation when driving is the key word.
I drove 1700km last week with my family for vacations , trunk was full (heavy luggages), bad weather conditions (rain, coldand snow a little bit). Motorway 80% and the rest of the trip were roads in the campaign for 20%

Speed limit on motorway (France is 130km/h or 81 mph) and on the roads, it is 90km/h or 53mph)

At the end of the trip, total average was 8,29 l/100km or 28,37 MPG (US)

We can reach easily 7l/100km or 33,6MPG(US) or even better 6,3 l/100km or 37,3 MPG(US)

To reach this, anticipation and smooth accelerations when driving (do not drive with the cruise control on motorway, consumption increases much more, I know it is less practical but it's really a significant change).
In addition to this, when driving in residential areas, cities and high traffic density portions, try to optimize your battery recharging cycles (use brakes and deceleration as much as possible by using B position of the automatic gear box) before arriving at home if possible otherwise, when the motor recharges batteries, consumption is increasing significantly if your speed is insufficient.
Pulse and glide in congested traffic areas is also something to bear in mind. Adapt your driving style with the relief of the road.

Traveler1

TampaOwner,

It sounds good! looks large improvement! Congratulations! I think you'll get better one by driving with monitoring instant MPG to feel ICE's On and Off.

Alpy64,

As for S position I had used it to get better regeneration. Since Prius users say B position works better to brake for regeneration. Yet I do not use it now. Because I found ECU makes using regeneration brake instead friction brake mostly with smooth pedaling, until less than 10km/h (6.2MPH). Using S-1 position, it looks using regeneration brake below 10km/h sometimes... (observing CAN data @ 7B0)

Cruiter

It's odd you mentioned this. I usually use cruise when the speed will be steady for several miles but I've also discovered the mileage seems to go up when I drive with just my foot. But the dammed thing is so quite and smooth at speed I don't realize sometimes that I'm over 80mph . So I do use the cruise when it's convenient.

Traveler1

I think it's case by case. I usually use the (rader) cruse except the situations:
1. downhill
2. crowded highway

As for 1, the cruse controls its speed by braking. Because of avoiding loosing the potential energy, I control the gas pedal by monitoring the power meter. As for 2, generally to say, people tend to drive keeping the constant distance from the front car rather than keeping the constant speed. The rader cruse works as the "people", so I turn it off to keep the speed as possible.
How do you think?

TampaOwner

just took it in a 25 mile drive, half highway going 70-80mph and the ither half local road traffic (but no stop lights)... and averaged 30.6 mpg... i gained 1 mpg at the end when my last 1.5 miles was EV battery only... so does everyone pretty much drive in Econo mode all the time? thats not bad for the car right?

kitlz

Eco mode is off for me now that it's cold out. I kept it on for the past two winters. I couldn't get warm during my mostly city commute of 10 miles or less. With eco mode off, the engine warms up quicker and I have heat. As far as mileage, I find it's actually a bit better than keeping eco mode on. Still have to deal with the hills though

Cruiter

That's about what my graph reading since OCT 2010 is reading. About 31mpg. You're getting about the same. The city mileage (properly driven) is definitely better.