This is my second year blocking my grill. Last year I only blocked the top, and this year I included 2/3rds of the bottom. I hope I am erring on the side of caution in protecting my G2 inverter cooling. I have a SG that reports radiator temps. No spikes over 198F, and most of the time 184F. I take the car to work 95 miles away where it sits for a couple of days in cold soak, and then I drive it home. This week ambient temps were 25 - 40F during driving, roads were dry, humidity low, and air thin at 6000 - 7500 feet. I set the cabin temp for personal comfort after the ICE has warmed up past 150F or so. This takes a couple of minutes. Round trip MPG: 58.5. This is about 5% less than my typical in moderate spring or fall weather, and I am delighted at the minor hit in fuel economy. Not exactly new news, but the astonished reports of EV drivers losing 1/3 to 1/2 of their range in the winter is making me feel smug.
So that looks about perfect. I have been blocking 100% without a scan gauge. I think I will remove the bottom row. Are you not blocking the lowest row? H
I've got both grills fully blocked and still it takes 20-30 min. to reach 70-80C coolant temp. The thermostat doesn't open fully until 85C so I suspect there is minimal flow through the radiator. I leave the heater in "auto". Have to use front defrost for the first 5-10 min. so I can see where I'm going (this is kind of necessary ). If I can get clear road with conditions good enough to go 70 km/hr (about 45 MPH) I can get piping hot air out of the heater in a few blocks. Otherwise it can take 5-10 min. before I get nice heat. You can reduce the mileage hit by turning off the A/C (auto) whenever you stop, allowing the engine to stop at lights. I don't bother to plug in the block heater as it has minimal effect at these temperatures (-25C out there now).
i just blocked my grille for the first time. made two 15 mile round trips to work so far, temp in the 20's. haven't noticed a difference, hanging in around 50mpg.
Hi Hal, Keep in mind my car is a G2. Air intake has an upper and lower section. I completely block the upper section, and the upper 2/3rds of the lower section. The blocking pattern for the G3 Prius intended to keep air flowing towards the inverter radiator will be different. Ken from Japan posted a thread on the topic, and is the most informed I think.
I block all the top and 2/3 of the bottom and I use the block heater for a couple hours before heading out. I think the ebh helps even at the -20c we had this morning ... takes at least several minutes off the warm up time. I use the heat sparingly until it gets to 70c if I can take it and the windows aren't frosting... 10 to 20 minutes. I think I'll block the rest of the grill tomorrow so I can get more heat into the cabin.
I am sure you can block it completely with -20 temps. My car is in Victoria blocked 100% without issues. I have had it blocked complete at +12c without the light coming on.Not sure how far I can push it? H
