hey hybrid lovers..
for our own community
hey hybrid lovers..
for our own community
Its been almost a year now owning my '05 FWD FEH and posting here. Learned alot on improving mpg from here and greenhybrid.com (GH). GH has been bought now and I've basicly said good by to that site. Hope Brad can do some upgrades to this site to increase visitors and members for its future. Others from GH are talking about creating a new Hybrid Site which will include Fuel Efficient (FE) enthusiast also.
Here is a tip I picked I up from Wayne Gerdes (xcel) after running some test on coasting. Normally, I coast as much as I can to improve MPG but I had no idea it could be improved so much.
The Coasting test was done like this per xcel instructions:
Get up to 43mph, shift to "L", at 40mpg, there will be a drop in RPM's. At this point, shift back to "D" and go electric vehicle (EV). Coast in drive to till you must shift to "N" at 10mph so "creaping" will not take place in the FEH. Continue untill coming to a dead stop. Take a measurement of that total "Glide" from 40mph to the stop. My results was .5 miles.
Next, do the same things but when you go EV at 40, shift to "N" (neutral), turn off the key and coast to a dead stop. My results was .68 miles, a 36% increase in distance.
After seeing the results, I tried the test without turning off the key and coasting in "N". My results was .6 miles, a 20% increase over "D" coasting in EV.
Took the testing two steps further and tried the coasting with the engine running (no EV). With the engine running, your burning a little fuel coasting of course, but we all know from those with the nav energy screen at idle coasting your at max instant mpg >60mpg most of the time.
Coasting in "D" engine running (used AC max) from 40mph to 10mph shifting to "N" and to a dead stop. Results was .6 miles, the same as EV in "N". It seems the engine took the drag off the gear set better than EV in "D" coasting.
Coasting in "N" engine running (used A/C max) from 40mph to a dead stop. Results was .82 miles. This is over a 36% increase with engine running in "D" coasting.
One important change from the standard automatic transaxle to the eCVT is that it does not have a torque converter. It is not damaged by coasting in "N" like other automatics. In fact, the manual states that you can tow the FEH up to 75mph with both the FWD and AWD tires on the road. The eCVT is a drive by wire system and there are no gears change machanicly when changing the shifter except "P" (park).
Does anyone realize here the benifits of gliding in the FEH in "N" yet. Let here from you Toyota Hybrid owners also.
Gary, I don't think your measures are really comparable. For instance, in N your coast is probably ending up with less charge in the battery than you have with the same coast in D.
Good point Jim
You are correct about while coasting in neutral, there is no charge going to the battery during EV gliding. There is very little regen in gliding or coasting in "D" either. In both situations, when coming to a stop, I shift down to "L" before applying the brakes to get max regen. Low is not a gear but is the wheels and axles turning the traction motor/generator while slowing and charging the battery. Also to capture the most posible charge while the ICE (engine) is running in the pulse back to the desired speed, I use what I call the "Fake Shift". The best way to perform the fake shift for recharging the battery is to watch the Assist/Charge needle. When the battery needs a recharge, the ICE is turning the generator providing a steady charge to the battery. However, by letting off the gas pedal, you send a high boost from the axles to the Traction motor giving the battery an even faster way to recharge the battery. Again, this is all seen by watching the Assist/Charge needle. Accelerate slowly and watch the charge needle come just to a point it shows no charge then release pressure on the gas pedal, the needle will show a large charge. When the the needle returns to a normal charge again, accelerate slowly (about 300 more RPM) till the needle is back off the charge position again and repeat. Continue as needed.
The fake shift can reduce the charging time and distance to almost half normal ICE recharge. A low battery is never a problem while using "N" for coasting in EV for the best FE. A round trip of about 23 miles using EV/ICE recharge above has gotten me over a 58mpg average at speed limits that averaged 33mph.
On the other hand, coasting in "N" with the ICE running is not a problem at all for me. While gliding/coasting in "N", the ICE is charging the battery if needed through the generator. Shifting back to "D" adds regen through the traction motor/generator. You can always use a fake shift in "D" to lower RPM's in your pulse if needed and pick up additional charging. When accelerating, I have choosen to take it slow if I can depending on traffic conditions. The scangauge has been very helpful determining the load at which to accelerate for the best FE among very many other things it does.
I think this discussion of how to improve fuel mileage has kind of gotten out of hand and away from really useful and workable suggestions for normal driving. I've had my FEH 2006 FWD for a little more than 3 months and put 1650 miles on it. Living on a small island, I drive only very short distances and try to do my best with soft acceleration and staying in electric mode as long as possible. Maybe 5% of my total mileage has been on soft beach sand that always requires a lot of power. My overall gas economy has been a very disappointing 22-23 mpg (only 5-6 mpg better than my 2002 Escape V6 FWD), and there seems to be little I can do to improve that performance. Cool weather and short trips that don't allow the engine to really warm up are negative factors, but I can't escape the notion that my particular vehicle is somehow poorly adjusted or engineered. These figures of 35 or even 40 mpg that I read of here sound completely fantastic to me. I'd be happy to get something like 26 mpg--it would be a 50% improvement over my old Escape! Right now it's a meagre 30-35% saving. Hardly worth the expense of the FEH. Any suggestions anyone?
Chris Feb. 15, 2006
Chris, can't help you with the soft sand driving, but you can still coast in "N" with the engine on or off on hard roads. Just speed up slowly to a higher speed and glide down to acceptable speed and repeat.
The scangauge (see scangauge.com) plugs in above the brake and sits on your dash (takes less than 5 min,) and can give you instant MPG reading. By seeing the instant mpg reading, you can learn how to improve your driving for better mpg. The cost of the scangauge is $129 and it does so many other things.
The term "normal driving" you use tells me you don't want to change your driving habits or style. You can't have it both ways. I'm getting twice your mileage out of my FWD in ideal conditions but I have to make those short trips also. Example, this morning I had to run to a store (2 miles away) and return home. The speed limit is 35mph so I went up to 40mph, shifted to "N" and coasted back to 35mph. During the coast about an 1/8 of a mile, my scangauge showed I was getting over 70mpg while the engine was warming up and also charging the HV battery. I was able to return home a great deal of the distance in EV. I drive like this during all warm ups and throughout my day.
Hope this helps.
You're on an island- tropical climate? Are you running your air on MAX? If so, you're keeping the gas engine on. Try the lower A/C setting, which will help improve mpg. I live in sunny LA, and am getting 30/32 with the 2WD FEH. Driving in sand will keep the engine on, I'm sure. Coast whenever you can...no island pun intended.
Running the math I'm seeing that it could be the sand driving you're doing. If you only got 5 mpg on sand, it would only bring your average down to about 24 mpg (assuming 30 mpg on pavement).
This coupled with short trips with a lot of stop-and-go plus A/C or defogger could bring you down to around 20 mpg.
Try to run about 100 miles only on the road and see what your mpg is. A scangauge might help you identify your sand mpg for real.
Gary, Joan, et al--
Actually it's a cold island where I'm living, and this being the cold season of the year I never use AC and only very rarely and briefly the defogger. So that can't be the issue. The driving on beach sand certainly is a considerable detriment, but it really amounts only to a very small percentage of my overall driving. I'm perfectly willing to try the coasting technique, but it seems to me that if one has to go to that extent to come up with the manufacturer's advertised 500 miles per tank (i.e. about 33.3 mpg) that borders on fraudulent advertising. Next week we'll be taking our FEH off island and do about 1,000 miles of regular "mainland" driving (hiway and local) driving, and perhaps I'll get different results then. Keep posted.
Some of the people posting are getting low mileage. I notice many of those posts are in December. Is it cold where you live? ALL cars get worse mileage when it is cold, part of the physics of internal combustion engines. My friend with a Prius gets 30 MPG or less in the winter, 40+ in the summer.