Could The Gas Pedal Be Anymore Sensitive?

The last few days, I've been arriving at work at 6:30AM instead of 8:00AM, and I notice that when I use the open-earlier entrance to work I can stay electric all the way to my parking space, usually 17-19MPH.

This one isn't as flat a road as the other, so I have to go uphill for a stretch, but I'm pulling 99.9MPG so something is working better. Using the other entrance, sometimes when I pull my foot off the pedal I'm electric but lots of times lately I'm not.

So, in this case it looks more like how the car feels like running rather than pedal sensitivity. It's usually a touch cooler 1-1/2 hours earlier than my normal arrival time, but I don't know how much that could be helping.

Of course, when I show up at 8:00AM I can't be moving at 17MPH or else people would be mad at me, despite more than a few 10MPH signs...

 

Keeping the car in EV mode longer won't necessarily improve your mileage -- in fact it may even worsen it in some situations. Eventually the ICE has to kick in to recharge the battery. The goal is to make it happen when the ICE can be run at maximum efficiency.

I personally would rather let the car decide when to do it -- I have to believe it has a better understanding of the all the variables involved than I do.

Maybe I trust the Toyota engineers too much. :mrgreen:

 

Most of the time I agree with this. However, at work I'm about ¼ mile from the open road, so I often put it into EV mode until I'm out of the business park, so that the petrol engine doesn't start its warm-up cycle until I have some use for its power (although it seems to produce lower power during warm-up).

Generally, though, I think it's more efficient to let the car choose when to turn the engine on and off. And I think that running on ICE alone is a very good sign - there's no energy going to or from the battery, and therefore no losses associated with storage. Other factors are of course varying (engine speed, wind resistance) that shouldn't make this your only guide, though.

 

This does involve the car's decisions, since I haven't gotten the EV mod yet. When it feels like burning gas, no amount of feathering will help. I can pull my foot off the pedal and the engine runs on, even after a 15-minute drive to work.

Unless, of course, the car feels like running off the battery. After the same kind of trip. Like it tosses a coin or something...

 

Generally, I agree that the car knows best. But there are exceptions:

1. When I know that I'm going to drive just a very short distance, I don't want the ICE to go through its wasteful warm-up cycle.

2. In winter, with the heater running, the ICE never shuts off. Even without the heater running, in extremely cold weather the ICE runs almost constantly to keep the CAT warm. Eventually there's nowhere for excess power to go and the hybrid advantage is lost.

I expect a measurable improvement in winter mileage now that I'll be able to drive the last mile or so of my 3 or 4 mile commute in EV mode. I'll burn no gas during that mile, and the battery will be recharged next time the ICE goes through its compulsory rapid-warm-up cycle.

 

My experience is the opposite. For instance, if I find myself at 55 mph in a 50 zone, I'll ease off on the accelerator, and it seems I have to keep easing and easing before the speed starts dropping. This the easiest car to keep at speed that I've ever owned, sometimes even to an aggravating degree (Qualifier: Past cars have been Audi and Saab sports sedans).

 

When you pulse dirve or feather the gas to control when the ICE kicks in you are making the descisions for the car. My point was just that I doubt that a human could make better decisions than the car can when you look at the big picture of lifetime MPG and emissions.

That's my point exactly -- the car knows something that you and I don't.

The EV mode switch is the exception. It has obvious benefits for certain trips that the car couldn't possibly provide automatically unless it was prescient.

 

Actually... I just realized it could. They could tie it in with the NAV system. If you set a destination that is nearby and doesn't require high-speed driving to reach, the car could choose to stay in EV mode.

Bah... it's probably too cumbersome to be practical (especially with the current interface), but it's a thought. And I know I would prefer that to hacking an EV button into my car.

 

My feeling is, that something is the result of that coin-toss I mentioned... :mrgreen:

 

Wheeeeee!!!!!

 

LungCookie Quote: When you pulse dirve or feather the gas to control when the ICE kicks in you are making the descisions for the car. My point was just that I doubt that a human could make better decisions than the car can when you look at the big picture of lifetime MPG and emissions.

I agree in the overall scheme of things. However, there are instances where I think the human driver can do better. As an example: coasting to a stoplight from a distance with a slight downgrade. With appropriate feathering, you can coast longer as you are not eating up kinetic energy in Regen and not kicking in the ICE to maintain speed. This is similar logic as to why Cruise Control is less efficient MPG-wise on rolling terrain. A human might tolerate somewhat more variation in speed taking advantage of the downhill sections which the computer cannot anticipate as it has no way of knowing what the terrain is.

Just my 2 cents.

Jon

 

as jchu says, on a straight perfectly flat road in 70 degree temperature with no stops, the car would probably beat me in 'decisions'.

But, in the real world, with other cars, stoplights, hills, curves, potholes, stray dogs, pedestrians, cyclists, bike messengers, taxis, pizza delivery cars, double parkers, emergency vehicles, ice patches and falling rocks, I beat the car, because I have information it doesn't.

I can anticipate and plan, it can only react.

 

on the Classic the gas pedal as on the 2k4 is a potentiometer and it changes the resistance to the computer or from the computer to tell the inverter to send power to MG2. What Rick and I have noted is that the pedal seems to travel further for a given amount of power from MG2 before the ICE cuts in. I leave work and travel almost a mile then have 2 traffic lights one block apart, the second light is at the start of a slight grade to an over pass then a 360 degree on ramp to the freeway that is going 55 miles and hour, so it's boot it up to speed and that fires the ICE and start recharging as we crest a bridge over the river and start a down grade for about 1/2 mile to catchup with the cars that are coming to a stop and crawl for about 1 mile to a traffic light. This portion is a 2% grade and then a light and another bridge over another arm of the same river. Then a down grade for about 3/4 mile to another light, 55 MPH again. The 2% grade portion is almost an impossibility for me to get the 2k4 to go stealth but the Classic does it with ease, I shouldn't say this but it did it today with my trailer in tow. The 2k4 has a difficult pedal to manipulate to get the car to move and stay with traffic on that section. If you leave so much as a 20 foot gap in front of you an 18 wheeler will cut in so most people do it bumper to bumper. Now I'm going to throw this in but at really low speeds in stealth the Classic has more power as far as I'm concerned because it operates at 273volt compared to the 200 of the 2k4, and yes as soon as the ICE kicks in, MG1 bumps it to somewhere between 200 and 500 depending on RPM which bumps the power up over the Classic. I'd still like to see the gas pedal have a more generous range at the start.

 

to be honest with ya, i had difficulties holding a steady speed too. also frequently (probably because the car accelerates so smoothly) i found myself going much faster than i planned. it was really noticable on streets where the speed limit was 35-40. the car just seems to hardly be moving.

so i started using the cruise control. now i use it for probably 80-90% of my driving. since i commute only 6 miles to work on the freeway, most of my driving is still city streets.

i find that anticipating traffic conditions makes it possible to drive even with one mph adjustments the cruise control provides.

also knowing how the car will react to various grades and popping the car in and out of cruise control has helped me greatly. i never did get mediocre gas mileage even from day one, but i feel that the cruise control definitely helped me in other than freeway driving.