Looks like the radiator is assembled all together, so the engine coolant would heat/cool the inverter coolant to an extent on it's own. After I did that 80mph test I pulled over and checked the inverter temp. It was warm not hot, maybe like 100F, this was down lower on the inverter, clearly not the cover. I'll have to keep an eye on it, but I suspect the cooling for it is way over kill. Looks like there's no xgauge for the scan gauge for inverter temp, 3rd gen has a bunch of temps and such.
Anyway, over 250 miles on this tank so far, got 3 bars left on the gas gauge, getting close to 1/4 tank. I suspect there's some sort of reserve too. The going 80mph really sucked the gas down fast.
Small update on things, I drove the car to a farther away post office (closes later) so figured it would give a nice trip to check mpg on. Started out 45mph with the cold engine since it seems to effect the mpg a ton at first at least. Once I got to the main road where there's a ton of traffic, I just went 55mph (basically everyone goes 60-65, some 70). On the way back I stopped at my dad's place for a bit and the engine cooled off enough to start up before power was needed (no hvac) but round trip driving mostly normal besides the 45mph area I hit over 50mpg, I think the trip computer said 51.2mpg. Not bad for the longer trips. I have a feeling getting 50mpg+ going to the close post office might be a lofty goal at 55mph, but at 45mph I think it can be done pretty easily.
I ended up buying a scan gauge, brand new on ebay for $140. The used ones are too close to new price, there's no real benefit buying used at those prices. I'm blown away the ultra gauges are so expensive now, they used to be like $50-55ish. I could really they they were cheaper built, the switches aren't great, and they aren't the most amazing at turning off, have had it kill the battery in my corolla a few times if it sat long enough, might be a side effect of cold weather in the winter too. I had zero problems with the scanguage.
Anyway, upper grill block I'll probably do, just the lower one was so much easier to do. Been pretty busy with my business, so haven't had a whole lot of time to mess with the car. Little things here and there. Need to assemble the back of the car together from doing the struts yet lol.
I wonder what the best way to stress test the inverter, and is there any known limits for temps? Generally speaking from the computer side of things, most devices are designed for 100C max, some lower temp stuff is 80C, but for inside power supplies and such 125C isn't uncommon. Clearly the coolant is going to the parts generating the most heat, likely not the capacitors. I'd guess their max voltage would be at least 80C (176F).
It shouldn't be too hard to run a temp probe and a cheap digital temp gauge somewhere to monitor the temps. Get a reading with block on at some consistent way of testing it, maybe do the 80mph thing again but at say 60mph and monitor average temp, then repeat with the grill block off. It's just packaging tape, so not like it's expensive to reapply.
I wonder if smooth hub caps would give much of an effect on the prius. I think I had a slight gain on my corolla. I just used simple coroplast zip tied to the rims and spray bombed to somewhat match the body color.
It's been a long time since I read about air dams and such, if I remember right, the concept was if the areo under the vehicle wasn't very good, the air dam was the simplest solution. With an air dam, I don't think there's much benefit from the under body panels since so much less air gets pushed under the car. I suspect a full underbelly pan would give some gains, clearly have to be careful about the exhaust, and the engine bay needs enough of a gap for the air going through the radiator to flow out of. Seems like the ideal setup would be to vent to the side of the vehicle where there would be a slight vacuum over some little vents. I suspect even better would be to use the vacuum at the rear of the car, but that's a long run.
I read on some prius models, the engine coolant went to the first cat to help with quicker warm ups. I'm guessing that's a 3rd gen thing, I don't recall seeing anything like that for 2nd gen. It would be neat to use the exhaust heat to help warm up the engine faster, say a heat exchanger to the engine oil pan and some sort of coolant heat exchanger. Clearly the issue is working with something that can handle both temp extremes (-10F or so to the max temp of the exhaust system). It would be nice to be able to disable the system once the engine is wamed up, since don't want to add more cooling demands. Also not sure what the effect is on cooling the exhaust gases, I suspect it shouldn't have much effect on how the engine runs since it should be a gradual thing.
Just for giggles, has anyone ran a boat tail on a prius? I've seen some pics online, but I don't see any mpg claims. Best I've seen was a box behind a prius and their mpg was like 51 average, the fuel log showed peaks of around 65 mph. No details on the trips though, like city driving, pulse and glide, higherway/express way driving, etc. The areocivic does amazing on mpg, I suspect a prius modified in a similar manner should give similar or better results even though it's a bigger/heavier car.