Oils4AsphaultOnly said:
GRA said:
Or it could mean that Porsche uses very aggressive tire treads with high rolling resistance, so that they can provide Porsche-level handling as demanded by their buyers. Of course, Porsche has also apparently chosen to understate their EPA numbers, as reflected in the fact that they easily exceed them in the real-world, while Tesla's EPA numbers are overstated and they, along with almost all other BEV manufacturers fall short of theirs in the real world. Tesla's numbers are especially optimistic because they use 5- versus the 2-cycle testing everyone else uses.
If using a two-speed transmission is such a bad idea, then why did Tesla opt for the one for the exact same reasons Porsche did (except they couldn't make one last)?
Of course, that doesn't explain why HEVs get better City than Hwy mpg. Are you claiming that regen is unrelated to that? After all, AFAIA every conventional ICE gets better Hwy than City mpg. yet AFAIA every HEV and PHEV gets the opposite, despite being heavier than a conventional ICE which should penalize them around town, where rolling resistance is a larger factor than drag. Serial vs. parallel vs. serial/parallel can shift the numbers around a bit.
"Or it could mean that Porsche uses very aggressive tire treads with high rolling resistance"
Give it up. High rolling resistance tires affects efficiency equally at ALL speeds.
Of course it does but as we know, at higher speeds drag overtakes rolling resistance as the major power requirement.
Oils4AsphaultOnly said:
The two-speed transmission isn't the answer you were hoping for.
It's an answer given the requirements Porsche (and Tesla) wanted to meet. As for me, since I don't need to have great 0-30 accel, nor do I need to cruise at 250kph, I'd probably be fine in a PEV with a single speed tranny transmission ratio (and/or motor power matched for efficiency) designed for maximum efficiency in the 50-80 mph speed range. Which is exactly the trade-off I suggested for the Bolt: 3 seconds slower 0-60 for a substantial (minimum 10 miles but preferably more; 5% of 259 is ~13 miles) range boost.
Oils4AsphaultOnly said:
As for HEV's getting better city than hway mpg - DING DING DING!! If even a combustion engine based vehicle gets better city mileage (due to regen) than Porsche, then that 2-speed transmission must REALLY SUCK!! Although Porsche could've sandbagged their numbers, that's neither here nor there for your case about 2-speed transmissions.
And you're misunderstanding the reason for why PHEV's get better city mileage than hway, despite "rolling resistance being a larger factor". It's NOT because rolling resistance increases (it stays constant), it's because drag decreases significantly (plot an exponential curve with speed). The city mpg for PHEV/HEV being better than ICE city mpg is ENTIRELY due to regen braking, but that's a comparison between different powertrains, not a comparison between city & hway mpg from within the same powertrain. You are mis-using data without any comprehension of what they mean.
The bolded section was exactly my point. Else, why would ICEs get better Hwy than city mpg? Efficiency and transmission ratios, with no help from regen.
Oils4AsphaultOnly said:
GRA said:
How is Porsche actually designing and building a two-speed transmission than can handle the torque when Tesla couldn't, and achieving what they set out to do, an 'unqualified' solution? It works. Or are you claiming that Porsche engineers are incompetent, and don't know how to design cars to meet their customers' demands?
Because the 2-speed transmission reduces the overall powertrain efficiency to the point of yielding less range instead of more
Do you have any actual data backign your claim? Porsche undoubtedly has the data, but AFAIA hasn't shown it to anyone.
Oils4AsphaultOnly said:
And Porsche didn't prioritize range, but priorized speed. Porsche's engineers designed their car to perform within the trade-offs that they were after. It's too bad that less than 2 years later, Tesla showed them how to get BOTH good performance AND range ... by using a single gear transmission.
Tesla in 2010 was less than 400 employees and didn't have the resources to solve ZF's 2-speed transmission issues. They're a much larger company now and they've determined that a 2-speed is still not worth the trade-off.
It's amusing that you would compare Tesla's engineering development skills to Porsche's. We agree that Tesla lacked the personnel to develop a two-speed tranny themselves back in Roadster days, but considering that they employ members of the public to perform beta testing of safety of life critical systems on public roads to this day, there's simply no comparison between the two companies capabilities in this area. Then there's the seemingly non-existent Production QC.
Oils4AsphaultOnly said:
GRA said:
I got it a long time ago. I'm a fan of LFP for a variety of reasons (safety, no cobalt, tolerance to high SoC, cost, cycle life being some), but primarily for city cars, as I don't think they can meet range needs for all-around cars. So, up to about 40kWh/150 miles I'm all for them. Whether or not LFP can provide the needed power in this case despite a high specific power remains to be seen, as we need full specs for the car, esp. the motor, transmission, and pack.
Of course you'd think that. And it's not "we need full specs", it's just you. The mental gymnastics that you had to perform to write that (despite what you wrote previously) must be amazing.
Just because LFP has a high specific power for a given capacity doesn't tell us whether it has
enough power to meet a given requirement.
Oils4AsphaultOnly said:
GRA said:
Actually, California has the final say (through CEC and/or CARB, I forget which) in how EA spends the $800 million they are forced to spend here by the settlement, just as the federal government has final say in the $1.2 billion EA has to spend in the rest of the country. If the government got the $2 billion in fines and then decided to spend it on building chargers, I assume you'd agree that was government-subsidized?
Now, if the only difference between the two situations is that in one case the government gets the money in fines from VW and then awards contracts to build chargers; in the other VW instead has to give the same money in lieu of fines to EA and then EA spends it how the government directs to build chargers, that's a government-subsidized operation for all intents and purposes in my book.
You have a very twisted mindset. I won't argue this further. FCEV's will die due to its own demerits anyway.
Fne by me - I want to see all the contestants compete on a level playing field without subsidies or mandates (for a given tech; the requirement should just specify ZEV), and let the public decide.