2010 Prius Grill Blocking strategy

I have grill blocked on a 08 & 2010.Under 5 mi. trips. Didn't see much of a difference.
35 to 40 avg. 10 below to 30 degrees. 40 to 50 mpg in the summer.
I kinda think if those excellent engineers at Toyota thought it was necessary they would have built shutters into the grills.

 

so edit the table below and give us your version.

 

I leave upper unblocked regardless of temp. I'm on west coast, if it were the interior I might revisit that, do 50% below freezing, but anyway. Below 0C I'll block lower 100%. From 0C to 10C I'll block lower 50%. Above 10C I leave it open.

 

It's that time of the year again, after not choosing to block my grill during the first winter I owned my Prius last year, and suffering some horrendous MPG drops for months, going to give it a go this year. Since Texas has such large swings in Temps, even in the Winter, decided to go with no Upper blocking and 75% lower grill blocking, using super strong Gorilla Duct Tape. So far, so good, in mid 40s lower temps this morning during my work commute, MPG's were just as good as when temps are in their 60-70s; as opposed to normally loosing 10% MPG in these temps with no grill blocking.

 

I used pipe insulation that has a slit on the side, trimmed it to length, and pushed it onto the grill bars. Worked well and stayed in place the entire winter.

 

I'll have to check in to see how well the Gorilla Tape holds up in a storm, but I like the look of the black tape better, certainly more inconspicuous than pipe insulation.

You're in Canada, I assume it's cold enough up there by now for 100% complete blocking

 

I used a dark grey insulation, it wasn't that noticeable and no adhesive to clean off in the spring.

 

To play it safe, I leave the upper grill open; the inverter coolant radiator's in behind there. With the lower grill, from around 8C down to 0C I'll block 50%, if it's persistently below 0C I'll block it 100%. If we're doing something like a run up Mount Seymour, I do NO blocking, just pull it all off. Once I start with the lower grill block I'll also seal up better, the gap between hood and fender.

I'm using foam plumbing pipe insulattion, the stuff with O.D. of 1.5", and a longitudinal slit. On the lower grill I don't bother to shorten it, just use the full 3' length, either one or two, depending on temp (per above). I secure it with a Velcro tape strip at both ends, easier to work with than zip-ties, and easy to take off and/or reuse. Here's the current setup, just one tube in (50%):



And here's a pic, using the same foam insulation, just pushed onto the seam at hood/fender junction. No need for tape here:

 

Now that I have a Gen 3, I've just reused my Gen 1 stair-tread solution, only flipped so the holes are up (in Gen 1, the inverter radiator was down).



I slip it behind the grille from above, just ahead of the radiator. Inconspicuous.

-Chap

 

Ken what material or steps did you take in blocking it?

Also do you have pictures? I'm presuming the upper portion is the small slit between the hood and front bumper?

Thakns
John

 

I know I'm late to the game here, but what is meant by 50% blocking of the upper grill?
A) Block all of the left (facing the engine), but none of the right.
B) Block the bottom half of both the left and right. (or the top)
C) Block the inside half of both the left and right. (or the outiside)

I'm a bit confused. Thanks!

 

Reporting in from Fairbanks Alaska. I just covered 100% of the lower grill and can already tell its making a difference. Temps are regularly -20 or -30 here. Car has a very hard time warming up, especially when I need that heat for my windshield and keeping me warm. Has anyone else noticed that Prius does a terrible job at defrosting in cold weather?

 

your engine temp is what's drawn into the cabin as heat. if engine temp isn’t warm, the air coming in to the cabin won’t be warm which will affect defrosting also. When I drive lower speed with ICE on, my engine temp drops to 188F when heater on high. I drive with lower grill blocks all year long depending on distance and duration of drives.

 

Here's a video I filmed 8 years ago with my 2010. It shows coolant temp (heat from the engine) and the opportunities it provides for engine off. On that day, I would have had the grille 80% blocked. I only did full blocking during the extremes of Minnesota winter.

 

Can someone tell me what is the normal operating temperature? When does the thermostat open? When do the fans turn on? I've got a 2010 with 178.5k on it. My new route is about 8 miles. There is currently a part where I hop onto a service road but I'm looking to cut that out. There is a route with what looks like all 45 mph speed limits. I plan to P&G a lot more. I just got myself a scan gauge 2. I took it for a 8~ mile drive on some faster roads. My engine was already somewhat warm. It wasn't until about 75% of the drive that it hit 190F. Also it was about 57F out. Earlier in the morning, it was a 42F windy rain. Thinking about doing some grill blocking. I hope if its usable, it will benefit engine life in my short, currently cold drives.

 

When I was using scanguage I'd often see temps level out around 150~170 F. Especially in winter. The thermostat I'd guesstimate opens around 180~190 F? It could be the fans are quiet, must be: I've never heard them come on, even with the AC, when they for sure would be running.

About the one time I reliably can run it up to 190~200 F is doing a sustained hill-climb, saying going up Mount Seymour. I would recommend to pull off all grill block if doing something like that, regardless of time of year.

 

195 F is where the engine wants to be. The thermostat will start to open at 180 F.