Trip results: Out West and through the mountains

Hello PCers,

This thread contains observations and thoughts collected from 4,766.4 miles of open road and mountain driving. If you want to see the pictures, check out this thread:
http://priuschat.com/forums/freds-house-pancakes/53701-im-outa-here-bit-2.html

My wife and I are back from a 17 day trip driving through 12 states. We started in Michigan, took a car ferry across Lake Michigan, went diagonally down Wisconsin and Iowa, and out I-80. Our ultimate destination was a climbing crag in Utah, and another in Colorado, but we made a lot of side trips and stops in between.

On this thread I intend to record some of my observations and experiences with driving our Prius for an extended trip. Instead of posting everything in one post, I intend to make a number of posts in this thread over the next few days. Don't hesitate to jump in and post your own thoughts, comments, and questions.

I'll start with the facts:

Total miles: 4,766.4
Total gas: 101 gallons (rounded off to account for starting vs ending tank)
Average mileage: 47.2 miles/gallon (US gallons)
Total cost of gas: $366.20
Average gas cost per mile: 7.68 cents/mile

Our best mileage was going through the Rockies at an even 50.0 mpg, including an 11,000 foot pass and a 12,000 foot pass. Our worst mileage was on the Interstate doing 75 mph, which is the speed limit in many of the
Western states. Keep in mind that much of this driving was at high altitude, going up and down and around switch-backs.

During all of the driving, we were running a 12V cooler which draws about 4 Amps. Part of the time we ran an inverter to charge the camera and other cordless devices.

Our Prius was packed to capacity, with two adults in the front, and the back over-packed with camping gear, climbing gear, hiking gear, clothes for hot weather, clothes for cold weather, and everything in between. We over-packed, or as my wife would point out, I over-packed. She referred to it as "unsupervised packing", correctly noting that I need adult supervision in most of my activities. The large cargo capacity of the Prius makes it easy to talk yourself into taking more than necessary. We had to carry water for camping, which added more weight.

My first observation: The Prius does amazingly well at high altitude. I had no trouble with the engine, no pinging or other problems, and plenty of power to make it up the big passes. Going up the big ones, the battery would drop to one purple bar, but the Prius still had plenty of power to keep up with the rest of the traffic. You have to be willing to use full throttle at times, but it works just fine.

On the 12,000 foot pass, I got stuck behind a pickup truck pulling an equipment trailer. He was hardly moving, and before I could pass I got boxed in behind him. We were at about the 11,000 foot point, and I had only one purple bar. As soon as I got an opening, I moved over to pass. We started almost at a standstill, and full throttle produced very little acceleration, but plenty of engine noise. With full throttle the Prius gradually built up speed. The faster it went, the faster it seemed to accelerate. Once we were up to about 20 mph the acceleration was fine. The Prius isn't a muscle car, but it has enough horsepower to go up a mountain, even after the battery is tapped out.

More to come...

Tom

 

Thanks for the kind comments.

As for gravel roads, we drove on some pretty nasty ones. Shelf Road in Colorado wasn't that great. If you like scary roads, take a look at this video (not mine, just one on youtube):
[ame=http://www.youtube.com/watch?v=8-j9k1Bp25c]YouTube - Shelf Road - Colorado[/ame]

Many of the service roads were worse than Shelf Road in terms of ruts, washboards, and potholes.

There are two problems with bad roads and the Prius: 1) Low ground clearance, and 2) Traction Control. I'll talk about each below:

1) Ground Clearance - The Prius sits pretty low for aerodynamic reasons. It also features a front air dam that is even lower. We only bottomed out once, and it was due to me going too fast. I was going uphill in gravel, and worried about the traction control kicking in, so I carried too much speed over some big ruts (they were hard to see in the failing light). I bottomed the suspension and heard a scraping sound from underneath, but an inspection the next day revealed no damage.

I think the key with driving the Prius on bad roads is to realize that it's not a truck. Go slowly, steer around or carefully through the ruts, and avoid rocks and anything else that risk high centering or damaging something underneath. The electric drive and low end torque make it easy to creep at very low speeds. If you remember what you are driving, you can go anywhere you would go with a normal front wheel drive car.

2) Traction Control - The traction control system on the Prius has been the focus of much discussion and name calling. It needs to be there because of the tremendous low end torque of the electric motors, but it can be overly sensitive and cut power at inopportune times. We found this out the hard way on a previous climbing trip to Kentucky, where I couldn't force our Prius to go back up the gravel drive from our cabin. We ended up unloading and just managed to get up the hill by going fast with an empty Prius. My passengers had to walk up the hill carrying our gear, and we reloaded at the top. In all fairness, this was a worse-case scenario, with loose gravel and the original OEM Goodyear Integrity tires. As long as I kept the Prius moving, it was okay, but as soon as it slowed to a stop the traction control would cut power and all I could do was sit there and listen to it go "woop, woop, woop..." as power was applied, the tires slipped, power was cut, and the cycle repeated.

This trip was a different experience. We now have Micheline MXV4+ Energy tires, and they work much better on loose dirt and gravel. I don't know if they would have worked on that driveway in Kentucky, but they worked well on this trip. After my experience bottoming out on the camp road at Shelf, I switched to going up at a crawl. Using this technique our Prius crawled up the hill with little fuss or bother. We had no trouble with slippage or traction control.

In summary about marginal roads: 1) Don't go fast; 2) Remember your ground clearance; 3) Loose gravel and sand can be a problem on uphills; and 4) Good tires will help with #3.

Take your Prius. It should do fine, plus you will save a lot on gas.

Tom

 

Well stated. There is enough power to go up any normal mountain grade, but you aren't going to win any hill climbing races. On the other hand, I didn't see many other cars going faster. I suppose it all depends on your priorities. A Prius would not be the first choice for The Race to the Clouds on Pike's Peak.

Tom

 

More...The NAV System:

Our Prius came with the factory GPS NAV system, and we have used it extensively on other trips. We are still using the DVD that came with the system in 2006, so some of these comments will be out of date, or related to out of date map data.

I like the built-in NAV system for a variety of reasons, not the least is the fact that it is built-in. The large screen offers a lot of real estate for split screen display in highway mode, and it's easy to reach. On the negative side, some of the user interface is a bit contorted, and the lockout when moving is annoying.

Our first problem came from out of date maps. This hasn't been a problem in Michigan, but it occurs to me that Michigan hasn't built any new roads in about 20 years. The economy in Michigan has been bad for a long time. While the rest of the nation debates whether we are in a recession, those of us in Michigan just sit here and say "Are you kidding me? Recession nothing, how about depression." Anyway, as soon as we got off the boat in Wisconsin, we got onto a new highway that wasn't on our DVD. It was interesting to watch the MFD screen show us driving mile after mile through empty fields. When we would get back onto known roads, Jill would wake up and chime in with directions, to which we would reply: "Well, welcome back Jill. Did you have a good nap?"

Obviously I can't blame the navigation system for out of date data since I haven't purchased the update, although I do wish the updates were more reasonably priced.

As we got farther West, more and more of the side roads were not on the maps, or if they were, had no turn-by-turn guidance. I now understand why many of you living in these areas complain about the lack of detail in the maps. You have my apology for any arguments I may have posted to the contrary.

Our second problem was the damnable lock-out while moving. For the entire trip, one of us was driving and the other riding shotgun. It was extremely frustrating to not be able to look up hotels and enter data while moving. Toyota needs to address this issue. Obviously, I can overcome this problem by hacking the system, but I shouldn't have to do this.

Here is another weird problem: The entire state of Utah was off by two miles, or at least all of the highway exits were. They were spot on geographically, but the exit numbers were all displaced by two. At first I thought they were new exits not on my map, but then I realized that I had extra exits on the map. Eventually I realized that there was a one-to-one correspondence, and the exits mapped by an offset of two miles. Perhaps this is fixed in on the new DVD.

Routing was another problem. Out West Jill was much more likely to come up with goofy or suboptimal routes. She would often suggest routes that were longer than ones clearly on the map. I though it might be a lack of data, but when we forced her to drive on our route, she would eventually get with the program and happily direct us the rest of the way. It was weird.

The last issue involves the three routing choices: Quick 1, Quick 2, and Shortest. Ideally there should be another option that provides the best of both worlds. The quick routes almost invariably routed over Interstate Highways. Sometimes we would want to take a more direct, diagonal route on secondary highways. Shortest was good for this, but when you select Shortest the NAV system takes you at your word. Jill will take every shortcut, whether it makes sense or not. She routes you through business loops on the highway, and over other undesirable roads just to save a few yards. I suspect she would use Walmart parking lots if she could. What I want is a "Reasonably Shortest" route, or something of that nature, which tells the system I want to take the short route, but not do business loops and other slow roads.

Routing wouldn't be such an issue if the NAV system had a better means for editing and saving routes. We had to use intermediate waypoints on several occasions to force a route. When we did this, invariably the intermediate waypoint was in a spot where Jill couldn't navigate, so the system would not automatically acknowledge that we had reached the intermediate waypoint. This meant that Jill would spend the next five minutes trying to get us to make a legal U turn, while I tried to remember the voice command to delete only the current waypoint, since the keyboard was locked out. :frusty: It was very frustrating.

At this point a casual reader will think I don't like the NAV system - not true. I still like the NAV system, and found it to be very useful on our trip. We located destinations that would have been very hard to find, and navigated through strange cities with ease. What I do think is that there is room for improvement.

more to come...

Tom

 

My thoughts too. I didn't make sense to drive a four wheel drive truck for 4,600 miles on the highway just for the hundred miles where it would help. That said, I do wish Toyota would offer a small hybrid 4x4. I'd go after that as a second car.

Tom

 

More...B Mode:

This trip offered my first chance to really use B mode. When you need it, it really helps.

On some of the mountain passes, D worked just fine. By the time we got to the top, the battery was down to one purple bar. Even on a long 6% downhill, if the traffic speed was high enough there was no need for B mode. The amount of power required to coast the Prius at 50 mph was enough to keep the battery from charging to the high limit. On occasion, even in this situation, I used B mode for convenience. It was easier to control speed with just the accelerator than switching back and forth to the brake.

It was the low speed downhills that really required B mode. At lower speed the aerodynamic losses are very low, so most of the potential energy from the altitude was converted to battery charge, and it didn't take much of a hill to max out the charge, especially if you started with a normal SOC. You are more likely to have a normal SOC at the top of a slow speed hill, so this was often the case.

Coming down from our campsite at Maple Canyon I could max out the SOC every time. It was about a 2,000 foot drop, and I couldn't go over 14 mph. I adopted the practice of going fast enough for regenerative braking to work, and dropped into B mode at the start. I would hit full green before the end of the hill, but by then it had flattened out just enough that B mode controlled the speed without the need for friction brakes.

Keeping an eye on the battery screen was very informative on the hills. I learned a lot watching it, but not so much that I risked driving off a cliff.

Tom

 

More...Refilling:

This extended trip gave me the chance to fill the gas tank on my Prius 13 times. I followed the usual advice about holding up the nozzle and filling on the lowest speed. Eleven of the pumps worked perfectly, clicking off when the tank was full. Two of the pumps were very fussy and clicked off repeatedly. On these two I had to manually hold the fill rate at something below the lowest auto setting, and even then they wanted to click off.

Here, I think, is the culprit behind many of the overfilling stories found on PC: With the two faulty pumps I was essentially defeating the auto shutoff, simply to get the darned pumps to fill my tank. I fussed around finding the exact flow rate to avoid click-off, but that also meant that the pumps would no longer click off when the tank was full. On one of them I put in 10.176 gallons having started with three bars! Only the gurgling sound from the filler saved me from a geyser spewing overfill.

So in brief, if your are attempting to fuel and find that you have to fuss to keep the nozzle running, watch out. Otherwise you may be adding your story to the long list on PC.

Tom