___The CVT based HCH-I can be coaxed into a very healthy increase over and above the EPA estimates when using the P&G technique where appropriate as well as general highway travel …
___Our mostly highway drive out to a test road near where I work is one that I commute on (the highway portion) daily. From a fresh reset Trip B before hitting the highway after picking up Tom at his home, we pulled into my employers training building at 72.2 mpg after ~ 75 miles and through an ~ 5 mph headwind … Not bad for a highway run in the CVT based HCH-I I thought?
___Onto P&G … The one item I was most concerned about while attempting a P&G in an HCH-I was the SoC after just a few attempts. After just 3 miles, both of us discovered that the HCH-I is self regulating just as Prius II is. I started out the days run with 18 of 20 bars and we crossed our fingers … After just 3 P&G cycles, the pack was hanging around 6 - 7 bars and I was beginning to get discouraged thinking this was not going to work. Like magic and on the very next pulse, I didn’t see any assist! I did however see a few bars of Forced charging just as it should. The Forced charging was enough to maintain a 6 - 7 bars SoC and we would not have any assist appear on any acceleration. That is if we could maintain this limited level of Pack capacity? It turned out to be a non-issue after all. That was easier then I had thought and for the next hour, we simply Pulsed and Glided to our hearts content and watched the SoC hang right around the 6 - 7 bar range just as it should … One puzzle solved, 2 more to go. What should the acceleration rate and speed ranges be to maximize her FE? It took about 20 of the 40 miles to come up with what we both thought was a good overall rate and range strategy as well as how to control the Pulse properly. This is what we found although I hope others would do some experimenting of their own to possibly find an even better rate/range for themselves. We tried ranges from 50 - 60 w/out a FAS, 50 - 60 with, 20 - 42 to 46 with, 30 - 44 to 46 with, 25 - 38 to 40 with, and 25 - 40 to 43 mph with. How we would judge the various rates and ranges is how high the Instantaneous would show just before we began the next pulse as compared to the last Instantaneous reading before the previous pulse. What appeared to give us the longest glide and maximized FE was the 25 mph on the low side and 43 on the high side with small changes in speed range in between depending on slight variations of the terrain ahead. So what did we come up with as far as Acceleration rates? While we were experimenting with the speed range, we were also commingling the acceleration rates. This is the cool part. Instead of relaying on the instantaneous, we began relying on the CVT’s RPM. We tried 1,800 - 2,000 RPM, 2,000 - 2,200 RPM, 2,100 - 2,300 RPM, 2,200 - 2,400 RPM, 2,300 - 2,500 RPM, 2,400 - 2,600 RPM, and 2,500 - 2,700 RPM. What appeared to be the most optimal was a 2,450 - 2,650 RPM rate. It appears as if we have a very good overall strategy including a range of 25 to ~ 43 mph, and an acceleration rate per the Tach of 2,450 - 2,650 RPM.
___Let me talk about the P&G as it pertains to the CVT based HCH-I to the letter. At the top end, you pull the CVT into Neutral at the same time you take the Key to IG-I to shut down the ICE. After about 2 seconds, you reboot (take the key to IG-II) and hold your glide/coast. At 25 - 26 mph, you take the key to IG-III to start the ICE and as soon as she turns over, back to IG-II and place the CVT into D or Drive. After ~ 1 second, the idle w/ tranny engaged should have stabilized out and you can initiate the pulse. At first, you do not just lay into the accelerator at WOT or you will have CVT belt issues in the future. You slowly but steadily increase pressure on the accelerator over ~ 3 to 5 seconds until the Tach is showing what we believed to be a FE optimal 2,450 to 2,650 RPM until its time to repeat the Glide/Coast again. When climbing, the lower RPM, slower speed ranges might be better as there were some small climbs that proved to be mind boggling in terms of figuring out exactly what was the best strategy. We were guessing a bit but a small climb might instead include a 2,100 - 2,300 RPM Pulse and top end speed range of just 37 - 40 mph instead of 40 - 43 mph. We did not have much more time to hone in on what actually was the best solution for a given slope but the results either way were pretty darn good as seen below …
___Ok already, what were the results? Remember our first 2 runs had us experimenting all over the map so I would say they are not as representative as what we came up with on the final 2 runs. Before each run while sitting at a stop, we zeroed Trip B. Segment 1 and 2 had a head/tail wind of ~ 5 mph. Segment 3 and 4 had a head/tail wind of ~ 10 mph. Temps of ~ 75 - 80 degrees F to start and 80 - 85 degrees F at the finish.
Segment 1: 90.7 - 10 miles
Segment 2: 107.1 - 10 miles
Segment 3: 85.5 - 10 miles
Segment 4: 116.1 - 10 miles
___Average over the 4 runs was 99.85 mpg after 40 miles. Not bad for our first time out, both of us in the car, and with 14.793 tons of stereo gear in the trunk
Actually, probably less then 100 # of stereo gear in trunk but it sounded good
I want to add that after our third P&G of Segment #4, we actually pegged the Instantaneous after just 2 miles at 120.0 mpg and still gliding at 25 mph on what appeared to be an almost flat section of road. This was from a dead stop with a reset Trip B ~ 2 miles prior! We did not have the time to figure out that particular absolutely magical rate/range on that particular portion of that segment and I doubt we will ever see it again in the near future but it sure was fun seeing it with both of us in absolute awe!
___And on the trip back … an ~ 10 mph tail wind for 60% of the drive and we hit the off-ramp at Dempster and I-94 with 78.x mpg after 65 + miles displayed. I did not have my I-Pass so we had to come to full stops and sit in line at all 3 toll plaza’s. Given this was not my normal off-ramp and routine, I missed about 3 or 4 FAS opportunities I always take in the Accord so she was doing very well indeed! Tom helped me quite a bit with how his CVT based HCH-I loves to ride the 80 mpg mark while traveling between 51 and 58 mph. I didn’t believe him at first but sure enough, the proof was shown to me in the display!
___That wasn’t the end of this ride however … Now we had the city traffic to deal with. Fortunately, Tom knows this route and was keying me in on local light timing. We were P&G’ing with our new found range/rate just as we were out on the test road earlier except we were performing the technique amongst traffic and intersection light after intersection light … The good thing is that his HCH-I’s FE was still increasing from the 78.x on the off-ramp all the while driving through some of Chicago’s finest traffic intersection nightmares! We were catching traffic and lights as if guided by a divine hand while the rabbits around us would trip them up ahead and let us sail on through in either a Glide or a Pulse depending … By the time we pulled into his parking spot deep in the north east side of Chicago, she was sitting at 80.2 mpg per the FCD. I didn’t think we were trying that hard and given I could not use all of my own specialties (Tom would not let me use any Drafting techniques
), Tom’s HCH-I proved its worth once again. After all was said and done, Tom’s HCH-I proved not only she could achieve excellent 100 + mpg segments using a pure P&G technique where appropriate, her highway hypermile capability can hold its own with the best of them! It is not often you receive Insight like FE while out on the highway so I was very pleased with Tom’s HCH-I results! Given this was Labor Day, traffic was a bit to light to maximize her FE with my own specialties but she definitely proved her worth in my eyes today!
___I hope some of you can use pieces and part of what we discovered and maybe even improve upon them! If Tom were given an 06 HCH-II, he would be valedictorian rated by tank #5 quite easily vs. trying to break through 2 + years of mediocre tanks after learning the ways of a hypermiler 2 years to late
I am absolutely sure of this given what he is capable of today.
___And another thank you to Krousdb for perfecting the P&G technique in his Prius II so that others driving whatever type of automobile can share in this new found wealth …
___As always, I am really impressed by the FE one can receive from a hybrid of any type when pushed. It is one thing to crush EPA estimates in a non-hybrid but it is another altogether to crush them in a hybrid and receive 80 + mpg in the process
I do not see any non-hybrid’s doing that tank over tank, that is for sure
___Finally, Tom should be along to add anything I may have missed or correct any item that we may have seen differently …