Showing posts with label active cruise control. Show all posts
Showing posts with label active cruise control. Show all posts

462 Mile REx Road Trip: New Jersey to Vermont

We stopped at the Big Moose Deli in New York for some coffee. It's about ten miles from the Vermont border. 
Perhaps the most discussed topic of the BMW i3 is the implementation of the range extender for the North American market. In an effort to have the vehicle qualify for the California Air Resource Board BMW set restrictions on how and when the range extender can turn on, effectively reducing the utility of the REx. These restrictions are most apparent when attempting to use the car for long journeys which include drastic increases in elevation.

This topic has been covered here and on every other EV site extensively, and recently it was announced that BMW is working on a software update that will allow, under certain conditions,  the range extender to come on much earlier than the 6.5% threshold it currently uses. I am actually beta testing that software for BMW now, having had it installed on my i3 just last week. The new software also includes some other updates that will be standard on 2015 i3s and will be uploaded to current i3 owners sometime early next year.

However this post will detail a New Jersey to Vermont road trip that I took a few weeks ago, just before I had the new software update. My in-laws live in Vermont, and I had been wanting to take this trip with the i3 ever since I got it, but I just haven't had the time. Once I knew I would be getting the new i3 software which would be adjusting how the range extender would work, I knew I needed to make the journey before I had it done, so I could perhaps compare the difference in performance the next time I go.
The Active Cruise Control is awesome. I don't think I'll buy another car that doesn't have it. 
I have taken the car on a few 200+ mile round trips, having the ability to charge up before heading home, but this would be much further, about 250 miles there and about 210 miles back home. The trip there would be longer because we were meeting at a restaurant farther into Vermont before heading back to the house. A couple of years ago I installed a Clipper Creek CS-40 at my in-laws' house, knowing that the day would eventually come when I drove an EV there, but I had never used it until now. My previous EVs (MINI-E and ActiveE) would have just been too much of a hassle to try to make this long of a trip, but the range extender is perfect for an occasional trip like this - or at least I hoped it would be.
Most of the roads in Vermont were covered in ice and snow. My new Blizzak snow tires performed very well and I definitely recommend them for i3 owners who need to drive in the snow.
The truth is, I really didn't know if such a long trip at highway speeds, which would include an overall elevation gain of nearly 1,000 feet would be doable without the car going into the dreaded reduced-power mode, where the vehicle slows down for a while so the REx can replenish the battery a bit. Also, in the final 50 miles of the journey I needed to climb 500 feet before descending 500 feet and then climb about 700 feet to our destination.

My wife and I set out early on a brisk morning with the temperature being only 15 degrees when we left. I didn't precondition the battery or cabin, and the total weight we were carrying was about 450 lbs between me, my wife and the items we were bringing up to her parents'. I topped off the gas tank the night before and left fully charged. The trip is nearly all highway and my plan was to set the cruise control for varying speeds between 70 mph and 75 mph to see how fast we could go with the REx maintaining the state of charge. I would drive the whole way there in Comfort mode and possibly use Eco Pro for the return trip.
A few blocks from our destination we came across some cows.
The combination of the very low temperatures, using the heated seats, cabin heat and  driving 75 mph meant the range extender turned on after only 48 miles. That's the earliest I had ever seen it turn on before. I had barely made it to the New York State border and I was already running on gas. So now I had a little over 200 miles to go and it would be all done on the range extender. I figured I'd need to stop three times so we searched the GPS for gas stations that were directly along the route and at the intervals we needed. I wanted to stop when we had about 10 miles of range left and we were able to pretty much get close to that on all three stops.

I needed to stop three times to fill up on the way there.
We made the first stop right about at the 100 mile mark which was about two hours into the journey. My wife laughed at how quickly the tiny gas tank filled up and we came up with the idea that she would time me on future stops to see how long it took to fill up. She would use the stopwatch app on her phone and we would start it when we exited the highway and stop it when we were back on the highway to see just how long the diversion was. We averaged a little over 2 minutes per stop and the best time was one minute, forty eight seconds. All three stops added a total of about seven minutes to the trip - not exactly much of an inconvenience.
The car looked like I was off-roading all day when we arrived. I finally got to test out the EVSE I installed at my in-laws' house over two years ago. Thankfully it worked.
For most of the trip I had the Active Cruise Control set to 70 mph, but I also spent some time with it set to 73 mph and 75 mph. As I expected, 70 mph seemed to be the sweet spot for holding the SOC. Even with inclines that lasted for a mile or two the car never went into reduced power mode. When I set it to the higher speeds it could maintain the SOC on flat ground, but the inclines had the SOC bar graph getting dangerously close to completely evaporating so I kept it at 70 whenever I was going up any kind of hill. One thing I can say, the Active Cruise Control really rocks for long drives like this. It holds the speed, slows down when the vehicle ahead reduces its speed and maintains a nice safe distance. I used it for virtually the entire trip and it is definitely worth the cost if you do a lot of highway driving.
We arrived after nearly 255 miles. About 207 of those miles was done using the range extender.
So, we made it without ever going into reduced power mode. I guess there is no need to do a comparison trip with the new software since this trip went flawlessly. The only thing I can think of doing is possibly trying the same trip with the ACC set to 75 mph the whole way to see if the new higher REx buffer allows me to maintain the faster speed. As it is now though, 70 mph is definitely the magic number for long distance REx driving. If most of the trip is on relatively flat terrain, the SOC buffer is big enough for sudden bursts of speed for passing and to sustain climbs for a few minutes and a couple of miles. Even though it worked out fine for me, I'm happy that BMW is increasing the battery buffer so longer, sustained mountain climbing will be possible without going into reduced power. I haven't had enough time with the new software to really comment on how well it works yet but I'll do that soon.
The final stats for the trip
The trip home the next day was pretty uneventful. I did precondition this time and drove the first half of the way in Eco Pro mode. It was also about ten degrees warmer. All that combined to allow us to go 15 more miles on battery than we had the day before, giving us a total of 63 miles before the range extender turned on. We arrived home with 462 miles on the trip odometer and an average consumption of 3.4 miles per kWh. I filled up with gas about 1.5 miles from my house so we left and arrived with a full tank. Including the final stop to top off we made seven stops for gas (3 going and 4 returning) and bought a total of 9.87 gallons of gas. We drove 111 miles on battery and 351 miles with the range extender running and averaged 35.5 miles per gallon. That's a little less than what I usually average for the REx, but this was a continuous 70 mph for the vast majority of both legs of the trip so I expected it to be lower than usual. If we had taken our other family car like we usually do for our Vermont trips, we would have needed 19 or 20 gallons of gas or about double what the i3 needed.
Getting ready to leave for the return trip back to NJ
In conclusion, these kinds of journeys are definitely not what the i3 REx was really developed for. The tiny 650cc motorcycle engine isn't really engineered to operate for hundreds of miles at a time and I'm sure if it was subjected to this kind of use every week it would certainly have premature mechanical issues. However using it as I do, for the occasional 10 or 20 miles here and there, or the final 3 miles on some days just to make it home plus a road trip every month or two, it's really a great alternative to spending an additional $20,000 for a battery that's triple the size of the i3's. The range extender model is a good stop-gap measure until there is a decent DC fast charge infrastructure in place, which is really the ultimate goal. BMW has some very good news with regards to DC fast charge infrastructure that they will be announcing very soon, perhaps even at NAIAS in January. They are making a significant investment in this area and I believe the EV faithful will be very happy when the news is announced.
Of course we had to return with some genuine Vermont Maple Syrup. The Maple-Walnut PB was a bonus.

BMW i3 Overactive-Active Cruise Control

When activated, the ACC displays an icon of a car on the road ahead of you. That means you are locked onto a vehicle in your path.
One of the coolest features on the i3 is the Active Cruise Control. The Parking Assistant is cool tech also, but honestly I can't see myself ever using it except to show it off to friends. I can park the car just fine on my own, and faster than the Parking Assistant can. The ACC on the other hand is not only really cool, but very useful.

Whether I'm stuck in slow moving traffic or driving long distance on the highway I'm finding myself using the ACC more and more. It's kind of like locking onto the car in front of you with a tractor beam from some sci-fi show and letting it pull you along. However there is one thing that needs to be improved upon with the i3's ACC. It will occasionally disengage by itself without warning. Yes, it does post a notice on the center display screen that it has deactivated, but unfortunately that is already after it shut off so it's not any real help. In traditionally powered cars, this is less of an issue because the i3 has such strong regenerative braking. When the ACC disengages in a gas car, it will go into a freewheel coast and be barely noticeable, other than the fact that it is gradually slowing down. In the i3, when the ACC disengages the car immediately goes into full regenerative braking mode and abruptly decelerates. It actually quite startling and certainly a safety issue because if someone happens to be tailgating you they could easily run into the back of your car.
The ACC seems to have difficulty driving when you are driving into direct sunlight

Knowing this, many of the existing i3 owners and I are always ready with our foot at the accelerator in case the ACC disengages, so we can quickly restore power to the motor and stop the vehicle from decelerating. It's something that you quickly adjust to, but if you aren't ready for it at the very least it's scary, and at worst a huge safety issue. It seems to happen much more when it's raining, and when the sun is low in the sky and you are driving directly into it. These things must confuse the cameras used for the system. I've also noticed that by driving under some low overpasses the system will shut off on occasion. Perhaps the system gets confused thinking the bridge is an obstruction in the roadway. BMW has advised keeping the windshield clean so the system can see clearly outward, but that is never an issue with me as I always keep my windshield clear.
It was raining when it disengaged this time

I believe the answer to this issue would be for BMW to change the software so the car freewheels like a conventional BMW if the ACC disengages by itself. The free wheeling could last for 4 or 5 seconds which could then be followed by the regenerative braking slowly gaining strength. This would prevent the abrupt deceleration that currently occurs when this happens and give the driver a few seconds to realize what just happened and act accordingly. Of course the ultimate goal would be to eliminate the self-disengaging of the system, but that will never be 100%. There will always be circumstances where the system gets "confused" and need to turn control back over to the driver.

I'll continue to use the ACC because it's really a great feature, but I'm always "at the ready" while using it. I wanted to write this post for the new i3 owners out there that follow here just in case you weren't aware of this issue. I was actually inspired by a follower of this blog who recently got an i3 and sent me an email asking about this. He was concerned that it was a problem with his particular car. So if you are new to the i3 and the ACC feature, just be ready at all times to respond with some throttle and you'll have nothing to worry about. I'm sure BMW is aware of this and already working on a solution. I don't believe it can stay like this without some kind of update to eliminate or minimize the abrupt deceleration following deactivation. At some point, it will cause an accident if not addressed.

Comprehensive i3 Video Review By Nissan LEAF Owner in the UK



It seems that nearly every day now there are new short video clips of i3 reviews posted on YouTube. When I come across one that I feel is done very well, I'll post it here. Such is the case with the above video made by Grant Thomas from the UK. Grant maintains a blog called "The Grant Thomas Blog: Sustainability, Electric Cars & Technology News and Comment" where he posted this i3 video review.

Grant owns a Nissan LEAF so he is an experienced electric vehicle owner and in my opinion that gives his review a little more credibility than some others done by journalists with very little real life electric vehicle experience. The video is about a half hour long and he does manage to cover a lot so pour yourself a nice cup of coffee (or a glass of wine), and kick back and enjoy!