I was experimenting with NICE at over 50 mph yesterday (I270 from Rockville,MD to I495 to TysonsCorner,VA; about 24 miles/60minute trip; temperature > 60F). I found that on a mild downhill grade ( < 15 degrees down, > 7 degrees down) and a long enough stretch of road ( > .2 miles), a warmed up engine ( Fwt > 160F, 30 minutes on), a HV Battery with a SOC > 50%, and over inflated tires ( 50psi front/ 48 psi rear) -- then on clear sunny day with a dry smooth road surface (whentraffic allowed it) - I could maintain a speed greater than 50 mph in Neutral without using any battery power or gas! The scangauge trip mileage indicator (AVG) also indicated that switching from Drive to Neutral on the downhills seem to help raise the highway fuel efficiency ( 70 mpg southbound overall 66 mpg northbound overall, with the hwy speed from 50mph to 60 mph) - I'm sure the lower speeds helped keep the MPGs up but on cruise control at 55 mph - I was expecting something around 63 mph not 66mph or 70 mph - So I'm thinking this technique is good for a 3mpg to 7 mpg boast in mpgs.
I believe you run the risk of over-spinning MG1 by coasting too fast in Neutral, but I'm sure someone else will be able to confirm or refute this.
Here is one of our old Gen2 topics that has some good information on gliding. http://priuschat.com/forums/gen-ii-...parison-methods-pedal-control-vs-neutral.html
He's in Maryland and driving to Virginia. In both of those states, like Maine, it's only illegal to coast in neutral on a downgrade. Of course, that means he was breaking the law.
Fixed your post. NICE-off-gliding is risky in the same way grille blocking is risky. But with grille blocking you can monitor temperatures.
True but SHM in D will net you 2.5L/100km (94mpg) in that same section, won't it? I fuelled up this morning (temps are 10°C/50°F and the engine is warm) and went on the 50mph highway and on the SHM sections, I can achieve 94mpg but they will be negated by the pulse sections to 56mph. One way got me 69.2mpg and round trip end up at 65mpg. The terrain was not flat and there were hills to climb with that 50mph speed limit.
Wow, overinflated tires and circumventing the HSD, all to try and eke a few extra miles per gallon from an already highly efficient automobile. It's also against the law, apparently, and might also aggravate other drivers, since it sounds like you're driving well below the speed limit. Not sure why it's work risking a blow-out or drivetrain damage, or why that last few miles per gallon are so important.
When going downhill under PC, at superhighway speeds my 2010 Prius tends to accelerate faster than I can modulate and limit the the speed using PC and the HSI. For that reason, in past inter-state road trips I have been using cruise control instead of using the recommended hypermiling technique Driving With Load(DWL). Going downhill, the electric motors' & ICE's ability to push the Prius forward becomes more effective and there's a sudden surge of power which I've found difficult to compensate for at speeds over 55 mph. When the Prius reaches speeds of over 60 mph, its fuel efficiency drops as wind resistance reduces the Prius' momentum. The other option is to allow the regen brake to slow down the Prius but they only recover about 30% of the energy - the rest of the energy is lost. Either way, my highway fuel efficiency drops when I use PC.
FL = Section 316.2024 <== repealed ( April 27, 2011) My preliminary review suggest that MA and PA are NICE state But the list of not NICE states is pretty long... MD = MD section 21-1108 VA = VA section 46.2-811 ME = ME Title 29-A. Subch 1 section 2064 CA = CA V C Section 21710 RI = RI Ch 31 Section 22-6 OR = OR Section 811.495 NM = NM Ch 66 Section 7-360 AZ = AZ Title 28 Section 895 CT = CT Sec. 14-222. ( for commerical vehicles) MI = MI 257.678 IL =
Hmm. It almost seems you have it backwards. In hypermiling terms, if you're going too fast downhill you've made a mistake by having excessive speed at the crest of the hill. Once you've reached the crest there's nothing to do except try to let gravity accelerate you to as high a legal and safe speed as possible. You want to do that by holding a steady gas pedal or brake. 100% warp is perfect, but otherwise a consistent level of regen is better than having to brake harder near the bottom.
