I'm glad you mentioned this. I do the same with my Prius but my wife has a different opinion about AC operation. If I have enough 'pins' the microcontroller could handle AC cycling and lead to a 'happier' time . . . the 'invisible hand'. <grins>

Bob Wilson

 

Bob, does anyone else find it tricky to keep the Prius in all electric mode?My brain really has to work overtime to tell my right foot to keep it in EV mode, especially if I want to accelerate from 29-31mph for example.A 5lbs foot attached to a 40 lbs leg is just too crude and instrument for such fine control.
Motorcycle riders(motocross racers,and maybe trials riders) have used thumb controls for a long time for slightly different reasons. My thumb is a lot more sensitive than my foot. Now, it wouldn't have to work thru the whole range of travel of the pedal, probably just the 1st 10-15%.
An old fashioned bicycle friction shifter might be a good starting point. I don't suppose anyone here has that on the top of their "to do" list?It wouldn't really improve mpg, but it would make low speed EV driving a less intense activity(for me). Thanks,Charlie

 

Mostly I use EV to sustain neighborhood speeds. The cruise control will work down to 23 mph but mostly I just catch EV as a way to "stealth" through a neighborhood.

Your NHW20 could get the EV switch mod. This would make it a lot easier.

Bob Wilson

 

On Honda hybrids (at least) you have three A/C modes:

• ALWAYS ON (this includes defroster mode)
• A/C off, fan only
• A/C econ that will shut off on autostop

I propose a super econ mode that uses the A/C only on coasting and braking. Maybe a fifth mode that also allows cruising but cuts the A/C during acceleration.

 

My car does not have an econ mode. With the new HCHII, the A/C can be run by ICE, battery, or a combination of the two--so, the A/C can run during the autostop. It also has climate control, which turns the A/C on or off to maintain the temperature it is set at. If you are bored, you can learn all about it here:


Honda movie

 

The jack rabbit start could be jack rabbit start/stop. There hasn't been any mention of gassing all the way to the stop light and then a fast stop. Learning to anticipate stoplights has been a big FE improver on my daily commute. If I minimize stopping and braking and conserve momentum my MPG climbs. I often coast in neutral especially when I know the engine braking will slow me down more than necessary. I know which situation calls for a little more speed to make a light and when too much speed will insure a stop. The pedestrian lights and cross traffic can tell a lot to anticipate when you will get a yellow/red and when you'll get the green though each intersection is it's own little puzzle.

When I first got my scangauge I was typically getting 25mpg on my daily commute, now 33 is my expectation and that's navigating 11 lights in 9 miles.

Starting from 15, 10 or even 5 mph instead of starting from a complete stop makes a big difference.

 

The majority of ones fuel consumption is typically used to offset air resisitance, which increases proportionally to the square of speed (if this is what you mean by wind resistance). Actual headwinds/crosswinds can also create a very large swing in mileage.

This depends. If the hills are gradual, rolling hills such as on a freeway, then these won't have too much of a difference, the key is being able to conserve momentum. If however you are on a steep hill, with lots of stop signs (like the one I live on) that is huge, as even the regenerative braking is not much help if the hill is so steep that you still need to brake anyway, and you must regain your momentum from each stop.

Also, going down a steeper grade will be less efficient than dropping the same elevation at a shallower grade as it will either: A) require braking, or B) accelerate the car to speeds with more air resistance.

This one can be quite big. Rain or snow especially will increase rolling resistance with the ground. Having a colder ambient temperature will also require the engine to take longer to warm up -- especially significant on shorter trips.

Hybrids can do decent in stop and go, but tank quickly if Air Conditioning is required, or if the stop and go takes place on a hill. The whole problem is momentum is constantly wasted.

This increases the tire resistance coefficient, not to mention tire wear.

This one depends. For me, AC costs almost nothing, as I run it when going down hills at max, and very little is needed to maintain temp when driving on the flat sections. I cycle it off on hill climbs. When AC is on, it will consume a certain amount of horsepower (and, consequently, a certain amount of gallons, more or less) per hour. So, AC will appear to hurt milege more if one drives slower, as it will represent a larger portion of their total consumption. Consequently, a hypermiler may rank this higher than an average driver when it takes the same amount of energy/fuel to do the same amount of cooling.

I find in practice that accelerating very slowly vs. rapidly makes minimal difference so long as I can preserve my momentum once I'm up to speed. It will require the same amount of energy to accelerate the mass of the car to a given speed no matter what, the differential efficiency of the engine at the respective RPMs is the issue, and on a CVT I find that it's about the same across a fairly broad range of accelerating styles.

This depends. If you're talking about flat ground, cruise is no different. On hills though it wastes quite a bit due to inability to drive with load. This is frustrating though as the cruise-control could be programmed to actually vary speeds with elecrtci priority first, then gas, in which case it would be an advantage over driving it manually.

These are essentially saying the same thing -- extra load in the car. The difference between a full and half tank is going to be about 35lbs. This will be more significant in a stop-and-go situation, as it gives the car a greater inertia. At steady speeds, the only effect will be a very, very minor increase in tire resistance (especially if offset with more pressure in proportion to the load)

Agreed:

Downhill/decelerating: Compressor on, full blower
Steady driving: Compresor cycles, just enough fan to maintain temp
Uphill Driving/accelerating: Compressor off

 

I always thought the top 10 were:

1. Flags out the windows

2. Cargo Carrier on the roof or other large equipment

3. Driving into a gale force headwind

4. Structural damage to the vehicle

5. Towing a trailer

6. Giant HAM radio antennas

7. Driving over 90 MPH

8. Leaving the engine running in park for 2+ hours

9. Accelerating as fast as you can before slamming on the brakes as often as you can rather than gently accelerating and making the next light green instead of stopping for it.

10. Never ever get an oil change.

 

My two cents worth...


1/ If you are lucky enough to live and work at the top of a hill...or grade, this will help a lot with FE. Because the worst FE is on startup and for the first couple of miles until warmup is completed. So if you are driving downhill for cold in each direction...this will help heaps.

2/ I firmly believe that 1/2 to 2/3 throttle on take off from the lights, using 4-6 bars of electric is the way to go. Let me explain. If you accelerate using only the ICE, you're not taking advantage of all that stored battery power. Why have an electric motor if you're not going to use it. By using it you ARE saving gas....but...once you reach nearly the desired speed...back off! Never flat foot it though! If you max out the electric assist you're really chewing up gas!

3/ Most of my breaking is done using regen. It saves brakes and recoups all that inerta. Ready for the next take off.

4/ Once you gain the desired speed this is where the fun begins. Try...try...try to be as light as possible on the gas to maintain your speed.

5/ I tend to increase my speed downhill (not using electric) so as to go up the next hill without using too much ICE. Quite often slowing down below the speed limit over the hill to gain speed again on the other side.

6/ Although drafting can help (following a truck very close behind) it wrecks your car with stone chips. Larger SUV's are not so bad!

7/ And finally, in very stop go traffic...I stop and go less. The car in front has to move at least two car lengths before I will.

8/ I believe that tyre pressure is important. I run at 40psi always.


My instant FE guage is in L/100klm so it's back to front compared to the U.S. The scale is 1 - 6 - 12+ L/100klm's. The lower the better. I try to always drive below 6. The best I've ever seen was 3.9!

 

What are you some kind of apologist for the SUV folks.

Context is everything.