2010 Prius Grill Blocking strategy

check out the 2012 Ford Focus with SFE (super fuel efficiency) package with its computer controlled front grill louvers... looks like "somebody" was reading this thread!

 

BMW was years ahead : in the '90's they came in Europe already whith the E39 525TDS with thermostatic controlled louvres in front of the radiator grille .

Now on the E90 , E91 and E92 3-series 320d Efficiênt Dynamics they have a simmilar system (maybe now electronicly controlled )

 

A few questions: I bought some 1/2" insulation. Just squeeze it into one slot right?

Also, what temps do I want to see on the engine coolant on Torque? What do I not want to see?

 

Yes, squeeze it in one slot.

Scangauge tells me 191-195, usually 193. You can watch it drop like a rock on very cold days when ICE-off. Should be fine quite a way over 200, but if I saw over 195, I'd take a piece of blocking out. No need to work the fans and thereby waste wh's.

 

Just blocked 50% of the bottom. Went much smoother than I thought it might. Looks decent too. Thanks for the help everyone!

 

Pulled together a little bit of data from the past month (September 2012). Gen III no grill blocking. A lot of people have been talking about observed maximum temperatures and so-forth. I've been logging the data in the Torque App for Android, so here's what I've been seeing.

Vehicle speed rounding in Excel using the equation "=ROUND([mph.xxx],-1)" - which rounds to the nearest 10MPH. Essentially, 20MPH = 20 +/- 5, or 15-25mph. 30MPH = 25-35mph, and so-on.

ICEInverter by bendertj, on Flickr

I'll probably start grill blocking this week, so I'll create a new chart later this winter with some of those results.

 

Is the foam pipe insulation that fits in a single slot 1" outside diameter? I have a new Gen III so I am getting ready to buy some material and do some blocking. Previously I owned a Gen II that I blocked with black foam but I had to cut each section in half length wise to get it to fit well in the slots. Is there a foam available that will fit in a single slot without cutting in half like that?

 

About to block mine for the first time today and still not sure which way to do so. Found a pic here of someone using 1 inch (???) insulating foam and apparently cutting it to wrap around the vents (click for pic CleanMPG Forums - View Single Post - New 3 generation Prius III).

I think I'm going to try to squeeze them between the louvers like in this pic http://john1701a.com/prius/photos/Prius_GrilleBlocking_CloseUp.jpg (probably not a prius grill, but you get the idea). I think this is 1/2 inch

 

1/2" inside diameter is > 1" outside, compression holds in place.

 

Yes 1/2" inside diameter works perfect. 1/2" will be the big advertised number that you are looking for on the packaging of the insulation when you go to the hardware store. Only other tools you will need is a utility knife and maybe a tape measure.

 

Hi Mendel Leisk,
Do you have the image still? If so, then may I trouble you to post it again? TIA

 

Yeah, kind of frustrating. Here it is:

 

Thanks! I am going to try to replicate this.
You mentioned that this insulation is about a foot, but is it the same diameter (1/2 inch inside diameter) as the ones you are using for the front grill blocking as well, or perhaps the diameter does not matter as you just sliced the insulation opened and used double-sided tape to keep it in place??

 

Not sure of your location, but in north america this stuff is sold as 3/4" pipe insulation. It has an inside diameter of roughly 3/4" (it's for insulating 3/4" dia pipe), and outside diameter of maybe 1 1/2"? It's pre-slitted the whole length, basically so you can just push this onto pipe. Very common availability, and this is the same stuff people are using for grill block at the front.

The stuff in the pic requires no fasteners, just push it onto the lip, which is crimped sufficiently to hold it in place. The hood when it comes down presses against it lightly, too: you can see the hood indent in pic.

 

Im sorry I don't really understand about grill blocking. Could someone tell me why do we need grill blocking and in what weather do we need to apply grill blocking? I really appreciate your answer!

 

Ahh, good to know. I have read earlier that folks were using 1/2" pipe insulation and was not sure if you were using the same. I am in southern California, but I hardly work with pipe insulation. However, now that you have mentioned the pre-slitting...it makes perfect sense. I was thinking of my kiddo's swimming noodles for some reason. LOL. Going to check out Home Depot/Lowes this wkend. Thanks!

 

Prius mileage stinks (relatively speaking) during warm up cycle. The blocking helps hold in heat, thus shortening warm up. Do it in very cold weather or in moderate temps with a tool like Scangauge II to monitor coolant temps.

 

You should just read the first page and see if you are interested in gaining a small increase in your mpg. There are links to photos as well on the first page. Seems like for CA, we should be at blocking only on the lower grill. How much blocking depends on the weather.
Good luck!

ps-others have also attributed the slight increase in mpg due to an increase in aerodynamics...

 

At super cold temps it is probably more that just a little increase in FE. I notice small increases even when the weather is in the 50's and 60's.

 

Temps in F:
86+ - 50% of lower
64-86 - 75% of lower
41-64 - 75% of lower and 50% of upper
below 41 - 100% of lower and 50% of upper

Above is Ken's recommendations from the very first post of this thread regarding grill blocking on Gen3 Prii.

I have a few questions:
Are those referring to average temps through the day or highs through the day or simply whatever the current temp is when you are driving?
Is this for city driving only? Certainly highway speeds might have a little different recommendations, correct?

Thanks!