First Morning with a Blocked Grill

Not sure if anyone posed this question already but...

Is there a "safe" combination of grills to block for use even in the summer (where temps in my area can go over 100F)?

Reason being...I don't have a scangauge... yet and I'm undecided if I should try this potentially risky mod.

 

<div class='quotetop'>QUOTE(Bob64 @ Aug 5 2007, 10:16 AM) [snapback]490900[/snapback]</div>

without a CAN-view or scangauge there is no safe grill blocking in 100F

 

<div class='quotetop'>QUOTE(Bob64 @ Aug 5 2007, 01:16 PM) [snapback]490900[/snapback]</div>

IMO, the upper grill can be blocked the fan starts. Haven't experienced constant 100F yet.

 

i used to think that, but after last winter (first full winter blocking grill) i am hesitant to suggest blocking when its warm out.

i tried to get my Prius as hot as possible this summer, and that included a lot of jack rabbit driving in near 100º heat with AC on max. temps peaked out at 195º.

now i FREQUENTLY had temps up as high as 203º when blocking radiator with OAT as high as 65º.

so my cutoff is basically going to be around 65º F. i feel that getting the car any hotter than this is not going to be beneficial.

as far as blocking the radiator and its effects. it is hard to make direct comparisons because my driving situation changed, but it should have changed for the worst. my commute was shorter, hillier and when not commuting i was carrying an average of 1-1½ (pregnant with 55 lb weight gain) more people. but my mileage went up nearly 2 mpg on average.

now this winter is coming, once again, my commute has changed. it will be longer (slightly probably close to 8-10 miles and pretty flat, havent clocked it yet but much better for mileage than my hilly 5 mile commute when i lived on the bay) so this winter should be revealing.

**edit**

a good comparison for differences in driving, on my 06 which i will have had a year in mid sept. i struggle to average 56 mpg summer mileage. have never had a 60 mpg tank. on my 04 that i drove 2 years, i had 9 60 mpg tanks and averaged 58 mpg in the summer.

 

Thanks for the good information guys. I am planning on blocking my grill starting in late October or early November, depending on temperatures.

 

I should take delivery on my 07 Seaside next week. I've been lurking in the background, reading various posts and soaking up info.

I would like to understand the blocked grill situation. I live in St. Louis and it is sometimes cold during the winter. The car will not be garaged. Is the Prius a cold-natured creature and will not want to start during cold weather or are you doing this strictly to increase your gas mileage?

 

<div class='quotetop'>QUOTE(07seaside @ Aug 31 2007, 11:02 AM) [snapback]504884[/snapback]</div>

The Prius starts fine in even the coldest of weather. It is a gas-saving technique. The ICE runs most efficiently when it's warm, and it will run to keep itself warm when it has to. In cool weather with cool air flowing through the grill, it warms more slowly and cools more quickly.

And welcome to PriusChat and Prius-dom!

 

I read in a japanese blog that over there, they use "sponge tape" to "block" the grill... considering that the temps in japan are probably around the 70's, has anyone in the US tried any sort of "sponge tape" (I'd imagine it to be something like the air filter material in central home heating/AC units)...

 

I think they are refering to the sponge tape you might use to seal windows and doors from drafts.

 

<div class='quotetop'>QUOTE(patsparks @ Sep 1 2007, 08:35 AM) [snapback]505369[/snapback]</div>

doubt it. since it mentions in the blog that it allows air to pass at highway speeds.

 

allowing air to pass at hi speeds is even worse for the themal efficiency of the ICE. Those of us with a means of checking the ICE temps long ago realized that in near freezing temps there is enought "leakage" to keep the ICE from over heating.

 

<div class='quotetop'>QUOTE(Bob64 @ Aug 5 2007, 01:16 PM) [snapback]490900[/snapback]</div>

I have had my upper grill blocked for over three weeks now in Augusta, GA. The Outside air temp has been between 70 deg F (am) to 100 deg F (noon) I use the ScanguageII to monitor temps. I drive in a hilly area on the interstate at 65-75 MPH(mostly 65) and short city rides too. I have not observed the fWT(Engine Coolant Temp) to be any higher than 193 deg F in this three week timeframe. I know others may post different findings....I am only giving info for my area of the country and driving conditions. hope this helps.

 

frank, please re-read my post in context (with my previous posts)
I'm looking for a solution for an all-year-round blocking solution that is "safe", even during the summer. Granted, the heat retention would be less effective with "sponge tape" (whatever that might be), but I think it might be something that is useful for people that want to boost efficiency without worrying about engine temps... (especially without an scangauge)

 

the safe solution to all year grill blocking involes a lot of issues. Most important is if your using the A/C I wouldn't consider blocking the grill at all, as the condenser covers all of the rad and not just the inverter portion of the rad. If your really handy and have the wherewithall to make a shutter system like they have on hi-way trucks and mount it so as to completely cover the rad area and have it work in concert witht the temp indicator system and a circuit to open it completely when the A/C comes on, then I'd say you have the means to block the grill regardless of temps and conditions. Till then, fall winter and spring with monitoring is all that is really required for getting the most thermal efficiency from the car with out any worring.

 

Jim - thanks for the info.

I'm anxious to get my hands on my Seaside!!

 

<div class='quotetop'>QUOTE(john1701a @ Dec 19 2006, 01:50 PM) [snapback]364231[/snapback]</div>

I'm picking up my first Prius tomorrow afternoon. I've been reading posts about the engine block heaters EBH and the pipe insulation during the COLDER months. I live in Madison, WI and like MN ... it can get rather cold. John is saying the the 1/2" size pipe insulation provides a better overall fit. Tony displays a package that describes 1" pipe insulation, (does he manually cut it in half?) and Wayne describes a "Prius-centric laser cut winter thermal mgmt. device." I'm confused and need direction/clarification on which pipe insulation works the best, before the cold weather sets in. Thanks in advance for your consideration and advise. [email protected]

 

The insulation that Evan uses he spreads across and then zip tie's to the grill. The insulation that Tony and I use is sized for 1 inch pipes, cut in half length-wise, each half folded in half and stuffed in each slot. Really your choice. If you can come to the next Milwaukee Hybrid Group meeting in October, I'll be doing a demo of the type Tony and I use. Might even have some extra available.

Wayne

 

<div class='quotetop'>QUOTE(FireEngineer @ Sep 10 2007, 10:00 AM) [snapback]510014[/snapback]</div>

I use two different sizes. It is more a matter of personal taste and available materials. I use the larger diameter insulation cut in half lengthwise and folded in half cut to fit the individual upper grill opennings. These are force or "compression" fit and are almost completely unnoticeable. I use the smaller diameter insulation uncut and placed around the lower grill. The two lengths are twist tied with black ties to ensure they don't blow off (as had happen on Barbara's).