AndyH
Well-known member
Sorry. I hope you're feeling better.GRA said:Andy, sorry for the delayed reply, I've been sick for several days.
The problem here, Guy, is that I'm talking about working with the results of standardized test results, while you're starting with a range target, arbitrarily derating it 40%, and declaring that the range won't work. Your error is in how you're manipulating the data, not on the decision you're making afterward. :lol:GRA said:As stated I know to take all of those into account, but if the car's max. range in ideal conditions is inadequate to my needs, all a year's worth of data would do is give me more precise information on just how much more inadequate it would be in various conditions, which would be a waste of my time.AndyH said:This is incorrect. I stated that I had to consider temperature, HVAC use, and terrain when planning my trips - but only for those that are to or beyond max range - not to the EPA range. This is important! (This is one of the reasons I wish you had at least a year of EVing under your belt because it's difficult to communicate without a common core of experience.)GRA said:You have stated that you slowed down, well below speeds that line haul trucks typically travel at.
And if you had real EV experience, you'd realize how far off this assertion is. The current EPA testing takes into account the typical Billy Joe Bob American driver with a lead foot and the AC blaring. And yet - commercial service is NOT like Mr. Bob running down the street burning rubber. Even the lead foot company drivers are restrained by company policies and governors - it's completely incorrect to say things like "my aunt Mable drives hard and therefore Musk's smoking crack". :lol:GRA said:Yet driving styles vary all over the place, and there are as many people who are unable to achieve EPA range as there are people like you (and me) who know how to exceed it. A company has to allow for the LCD, and something close to worst case conditions.AndyH said:My last EV was a city car with 68 miles of EPA range. As I reported in the Outl@nder PHEV thread, I find the new EPA profile to be pessimistic even with a fair amount of jack-rabbit starts and plenty of AC running. In my smart, I don't have to think to achieve the EPA range, though it is possible to get close to it. In routine driving, I found it easy to exceed the EPA range by 20% by paying attention, and by more than 40% by hypermiling. I can't say for sure if any of this will carry over to an EV class 8 tractor, but at the very least I expect the EPA range to be as conservative for this category as I've found it to be for diesel cars, an EV, and now a PHEV.
The test cycles have no bearing on the test cycles? :shock: All righty then...I guess we've hit part of Trump's demo walls here.GRA said:Thanks, but those have no bearing on the test cycles currently being used by the EPA for cars, and I'd be willing to bet that Tesla isn't using them either when quoting ranges for the Semi (if they're even using any EPA test); as yet, AFAWK they only have one or maybe two prototypes on the road. Let'd check back when a production Tesla Semi is actually available for testing.AndyH said:You asked at some point about test cycles pertinent to Class 8 tractors. One of the organizations certified to perform fuel, lube, and economy testing is SouthWest Research Institute here in San Antonio. (Just in case you want to drill-down into SAE test protocols.) The second link is for a couple of the more stringent tests - those outlined by CARB.
https://www.swri.org/heavy-duty-truck-fuel-economy-testing-evaluations
https://www.dieselnet.com/standards/cycles/hhddt.php
Note that the test used to evaluate 'high speed cruise' has a max speed of 59.3 MPH and an average of 39.9.
Ah yes - now you're back to telling me what I know and what I don't know. :lol: I've driven from Superior, WI to the Mexican border, and from Cape Cod to Sebastopol. The western driving includes the low route through Arizona and New Mexico, and from the Bay area to Denver to St Louis. I know how hot brakes smell, and how underpowered vehicles chug up hills. LOL I've also ridden along in trucks hauling 2000 gallons of gas and diesel up and down hills that are closed in the winter because they're too steep. Of COURSE Tesla's going to use some of their new trucks to run a ROUTE THEY NEED COVERED! My local grocery store is 2 miles away and I use an EV to get there - that doesn't mean that's as far as the car will go! :lol:GRA said:Written like someone who just did a long drive N-S on I-35 (highest point 1,578 ft. MSL), instead of E-W on I-70 or I-80 crossing the Rockies or Sierra, where the grades are often above 5% and have truck climbing lanes (and runaway ramps in the other direction), e.g. https://en.wikipedia.org/wiki/Interstate_80_in_California#/media/File:I-80_altitude_profile.png A BEV semi like the Tesla will be able to stay in the normal right lane instead of over in the truck climbing lane (typical speed -=45 mph) , all the way to Donner Summit (7,227 east or 7,239 ft. west), the Eisenhower tunnel (top 11,158 ft, 6% westbound) on I-70, Cabbage Hill on I-84 east of Pendleton, etc., and then benefit from regen on the way down (the parts with the runaway ramps and signs like this: https://imgur.com/gallery/wUrwF It's no surprise that Tesla is planning to use the BEVs for short hauls from the Bay Area to the Gigafactory (259 miles, net elev. gain of 4,700 ft. or so) and back.AndyH said:The ability to climb a hill is a good marketing metric, but it's not that useful in the real world when one is concerned with range/economy.
[/quote]GRA said:Yes, when fuel prices are high there's more incentive to slow down. Back in 2013 I had to drive 200 miles down I-5 (which is about as close as California Interstates come to the unending tedium of the plains states), and as I was early and had time to kill I was curious to see if I could drive 55 in the right lane without being constantly overtaken by semis at a time of high fuel prices (Note, California has a 55 mph speed limit for any vehicle pulling a trailer - rural interstate speed limit is 70). It was quickly apparent that no one was doing 55, so I decided to pace a variety of trucks to see how fast they were cruising; the slowest semi, a contractor hauling U.S. mail and who probably had an electronic log and/or gps telltale was doing 59. The majority of the trucks were cruising at 62-63, there were many in the 66-68 range and the fastest one I clocked was doing 69. A couple of years later when fuel prices were lower I had occasion to do the same trip, and being early again I paced trucks again. Now the slowest one was doing 63, the largest group were cruising at 67-69, and there were plenty over 70. In states without truck speed limits (and/or higher limits than California, which is all the western ones) they used to cruise a lot faster than that, but I have no recent experience so won't make any claims. It was bad enough then to see guys hauling triples at 80 mph!AndyH said:I say this because when I was advising tractor operators, from owner-operators to small fleet operators (10-25 tractors) it was during the period of high diesel prices before our current artificial low. Both categories of operators adapted their operation style to save fuel money. Owner-operators acted the way we EVers act - we slowed down a bit, understanding that drag increases with the square of speed. Fleet operators don't mash the 'go pedal' on their own. If they couldn't entice drivers with a cost share for saved fuel (a nice carrot), they turned the governor down on the tractors until the average speed slowed down enough to bring in the desired fuel savings. Lots of words there - let's shrink them a bit: Class 8 operators already actively manage fuel economy and range using the same techniques used by EVers. The way they fuel will change, and the range will change, but the rest will not.
Well there you go - you saw some guy driving fast therefore there's no such thing as governors. Gotcha. The folks I was working with were out of Texas and the companies were keeping drivers well below the 80 and 85 MPH limit on I-10 and on toll roads from San Antonio to Dallas.
Oh brother.