Recent content by Tessaract

I checked out my Ottawa Hydro bill carefully in prep for the ULO rates, and calculated that transmission, distribution, etc. amounted to about 2.2 c/kWh. Don't know your location, but perhaps your utility charges more for this.

Of course it's impossible to conduct a whole vehicle test at a precise single temperature in the real world. But perhaps you've noticed that the average of 68 and 86 is 77, so the NOMINAL temperature of the EPA "75˚tests" (EPA's own label) is near the midpoint of the range. One could argue that...

The EPA itself refers to these tests as 75˚F tests (to contrast with its 20˚F cold weather tests), because that's the nominal temperature. Of course, there is a temp range allowed, and my personal opinion is that this range is too broad and should be reduced to something like ±5˚F.

There are actually 4 control arms in the front, and at least 2 more in the rear suspension. If you've replaced the 4 fronts (as I have), it's still possible to have the rear ones start squeaking.

1) EPA consumption/range numbers are NOT guarantees of consumption /range for every driving condiiton. EPA consumption/range numbers are weighted averages which include SOME cold weather driving (20˚F), but more than 80% of the driving cycles are at 75˚F. These driving cycles and calculations...

Probably explained by new vs old tires. Tire rolling resistance can decrease by 20% as a tire wears. See my reply to akveluru.

It is fact that new tires have higher rolling resistance than worn tires. In fact, rolling resistance decreases about 20% as a tire wears and tread rubber is removed. So even if you put the exact same brand new tires on your car, you should not be surprised with up to 20% more rolling...

Not well known to normal people perhaps, but auto engineers know that worn tires have lower rolling resistance than new tires. It's becuase there is less tread rubber (in the crown of the tire) in worn tires, and therefore less hysteretic loss in that rubber.

Fortunately, the math has already been done in studies by people who like doing math and are good at it. So governments just need to grab some cohones and do the right thing, rather than play politics, which is what I smell going on in Saskatchewan.

Actually, it is. The sample size (number of flights) is large enough to put an upper bound on the failure rate. Such reasoning is standard practice in reliability testing. And with 4 anomalies in 100 flights, the number of anomalies is also large enough to provide a reasonable lower bound to the...

I also have such a cord (with 14-50 neutral removed, with a big label stating "for EV charging ONLY", which is only used on road trips. I've used it to connect to the stove plug in a cottage and a dryer plug under similar circumstances. Always set the car charging current to 80% of the breaker...

This is a terribly regressive taxation scheme. It's disproportional and projudicial. Fair would be to tax all vehicles based on road damage, which could be based on vehicle weight and yearly kilometers driven. That way the vehicles that caused the damage would actually pay their fair share.

Yikes! That COPD would have killed someone if it had hit them. And its all due to a failure of second stage to execute a reentry burn. It's the first S9 MVAC engine failure I'm aware of, and based on that, the probability of failure is less than ~4% ( 1 failure in ~25 LEO insertions). Not as low...

I think a similar prinicipal in generally operating in most areas that are deregulated. In a derugulated environment, things go reasonably well during normal times, but really fall apart during unusual times, precisiely because the benefits of deregulation result from cutting the corners that we...

Exactly. As an electical engineer I was shocked to learn that Texas has almost no grid interconnection out-of-state. It's a basic premise of electical grid resilience that it needs to be interconnected to other locales that have different consumption, generation, and weather patterns in order to...