LOL. That is because it is summer and very hot, not because it is 0W-16. An oil’s viscosity decreases greatly with increasing temperature. Try pouring it in subfreezing weather or after you put the bottle in a freezer.
Yeah, I doubt it is oil. More likely it's a software change to the VVT-i system. Maybe a little more aggressive on the intake cam when the system is asked for max power. There's no links in the NCF linking to any changes in the engine, so I'm fairly sure it's just software and no physical changes.
It is interesting that the torque hasn’t changed. It could be that they have increased the maximum rpm because thinner oil lets you run higher rpm.
OK, then, they must have increased the torque at high rpm. It is probably a software update, as you said.
Listed torque ratings are the same at 139 lbft at 4400 to 5200rpm for both the 2026 and 2027 versions. (188 Nm)
Although both will save you quite a bit of cash by cutting fuel stops, that initial hurdle is getting harder for many families who could use a good hybrid in their driveway. But if you can afford the $30,050, the LE FWD returns an astoundingly high 59/50/55 mpg city/highway/combined on the EPA cycle. That’s a change from the 2026 model year, which was rated at 57/56/57 mpg, as the 2027 model’s slight rise in city efficiency isn’t enough to offset its significant drop in highway mpg. Add AWD to the LE trim and the numbers fall to 56/49/53 mpg, both city and highway efficiencies drop from the 2026 model as well. We’ve reached out to Toyota to see what changed to cause the drop, as the engine, CVT, and body design do not appear to warrant such a decline in highway mileage. Mostly unchanged is the Prius PHEV's efficiency. It still gets 114 mpg-e combined on the XSE and up. The SE trim, however, is now rated at 129 mpg-e, up 2 mpg-e from 2026, but both trims’ combined gas-only EPA ratings are down by 1 mpg, now showing 51 mpg for the SE and 47 mpg for the XSE and above.
Okay, I guess that still works, because the bump in torque at 6000rpm(131.3 to 136.6 in the HEV) is still under the max torque for the engine at the lower rpm band. Regardless, I'm 99% certain it's just a change in programming. Either in the VVT-i programming, the transaxle programming, or some combination of the two. The engineers have probably been tweaking the M20A and the 5th gen hybrid system as they've added them to more models, and they realized they were leaving some safe power on the table. (I've been doing the research to see whether I can add dual zone climate with ionization to my 2023 HEV, which is why I've been doing a deep dive the last few days. It's looking good from a technical standpoint, but sourcing parts is going to be interesting if I want to keep costs down. Probably a mix of US salvaged parts, new parts from Japan, and at least one new or salvaged part from Europe that I have no idea how to source.)
