Warm Weather Pro Tip Search

[broski499]

Greetings. As the weather starts to warm up, I wanted to see what everyone is doing to maximize their MPG in warm weather. What are some must dos and some no goes?

I live in Southern California and we are already hitting the 90s this week. I have my custom prius shun shade always up. Whenever I begin my journey I have AC turned off and windows down to vent hot air. When possible/wife not in car, I don't use the AC. What are your thoughts on grill blocks in hot weather, risk of overheating? Anyone with an 08 prius ever experience overheating while having grill blocks? I've also looked into those solar ventilator things you put in your window. I have tested the As Seen on TV one and its total garbage. I also tested one from ebay that has an intake and exhaust fan with a larger solar panel, worked better but build quality was crap. Next idea would be to get a USB solar panel and connect it to a battery pack then use the USB fans to help vent hot air.

Anyway, what do you do to maximize mpg in hot weather with your hybrid?

[redpoint5]

I wouldn't bother with aftermarket cabin fans.

The Prius runs 1 radiator cooling fan whenever the AC is on, so this usually keeps engine coolant temps reasonable even with a partial grill block. I'd experiment with blocking the lower grill but keep an eye on a temperature gauge because running the 2nd radiator cooling fan is not efficient. You'll lose AC cooling efficiency with the grill block, so there is a tradeoff. In CA, I'd probably not block at all.

Seems like you're already doing what you can to improve efficiency.

I'll park with the windows down and doors unlocked, but then again I don't have any valuables in the car, and I don't live in SoCal.

[vskid3]

I run a lower grill block most of the year on my '05 Prius, but I remove it in the summer because the inverter gets warmer than I would like on longer trips. You might be able to get away with it if you're doing low speed, short trips. I would definitely use instrumentation that shows the inverter temp. Upper grill doesn't get any blockage until temps are below 40F.

I would recommend using some AC to try to keep the battery cooled. A toasty battery probably won't last as long and won't give as good of performance.

An EV mode button can help in all weather when used as an ICE kill switch. With the way the warm up stages work in the Gen2 Prius, you can easily get stuck with the ICE running when it doesn't need to be. The EV button can help fix that.

[redpoint5]

Originally Posted by vskid3

I run a lower grill block most of the year on my '05 Prius, ..

You just reminded me that that's the one I block. I leave the upper free due to the inverter being up there.

[freebeard]

Sounds like a job for a full boat tail.