2010 Prius Grill Blocking strategy

No one actually drives like that though. Pretty much everyone has some travel after leaving the interstate, where heat retention becomes a big deal. You are far more likely to have to deal with slower travel speeds too.

Remember, the gain for heat retention is quite noticeable with true winter conditions... temperatures well below freezing.

 

I wouldn't use any blocking once it get's into air conditioning weather. It makes no sense to me grill block and turn on the A/C.

 

Question, everyone says to get the insulation that doesn't have the sealing, well I went to 3 stores today and everyone had the sealing kind.
The closest home depot is 40 miles away.
Am I ok with the ones that seal?
Would it be better to peel the tape off and seal the ends together or leave the tape on and just insert the tubing?
Or should I just wait until I have a change to get to home depot for the right stuff.
Any input would be greatly appreciated.
Thanks,

 

What's the seal for? There's no need for anything to stick.

I just finished mine 20 minutes ago, doing nothing but squeezing 1/2" foam tubes between each grille slot.

That's same thing I've been doing for years. Works great.

 

the sealing type is slit from end to end with a sticky edge you peel plastic off of so you can apply to pipe after the fact. these work fine and i would peel and stick togetther so the plastic doesn't become a problem later on. it can peel off if things dry out.

 

An alternative to zip ties (for securing the foam tubes) is velcro strips. You can rolls of the stuff, and cut any length you need. Lee Valley is one source, it's in their gardening section, green colored.

 

Thanks Bisco for understanding what I was asking since I may not have been as clear about it as possible.
I was hoping if I just stuck them together and let them dry beforehand they would be ok to insert in the grill.

 

I've gone three winters without grill blocking, but on my Gen II my choice was the closed-cell "rubber" insulation used for A/C copper piping.

I just bought one 6' piece of 1 1/8" ID with 5/8 thickness. I cut it in half both lengthwise and across the width. The four pieces will allow full blocking of the lower portion of the grill. In the past I left the tape on with no problems. It isn't necessary to use the sticky part to hold the foam in place.

I prefer this insulation to the gray, open-celled foam, because the "rubber" foam is charcoal colored and looks much better in place.

 

Here's mine from ages past, same approach for each:


Note how the front of the car gets dirty, obscuring the look anyway.

This is with them clean still, basically easy to overlook even then.



They stay in place all season long, never any effort required after the initial install.

 

I just simply cut the pipe insulation to length and cut vertical slits to match the vertical fins of the grill. Then I inserted the pipe insulation around the horizontal fin of the grill. No need for zip ties, tape, velcro, etc.

I have had mine on now for about 3 weeks, since the morning temps have been getting down to the low 40s on some occasions. It's been getting up to about 70* during the day. When I monitor the water temp with my Ultra Gauge it goes to about 200*. It definitely helps my engine warm up quicker and somewhat maintain my mileage as the weather changes.

 

I picked up the insulation yesterday and cut it last night. Installation took all of about 2 minutes this afternoon.

I ran a known course this morning without the grill blocking, and I'll repeat it tomorrow morning to see if there is a clear difference in one short trip.

Here's a picture from this afternoon.

 

That looks good a priori, is that just the grey stuff?
I was debating all day if I should hit the home depot and get the closed cell black stuff. But I will end up using $8 worth of gas to get it, plus I will end up hitting Costco if I do.
So it would end up costing me like $308 to go lol.
For $2.97 and already in my house I may just stick with the grey

 

It is a dark charcoal color -- close to black.

I understand your hesitancy to spend more money just to change foam tubes. I have Sam's, Home Depot, Menards (local), Wal-Mart, Target . . . all within 1/2 mile of my home. Costco is more than two miles away, so I don't venture that far too often. There is a Meijer store half way along the route, so why bother? Believe me, I'd rather live farther away, but whenever I need something, it doesn't take long to find it!

 

Here's an early report on the effect of grill blocking. As I noted yesterday, I purchased and applied some closed cell foam rubber pipe insulation to block the lower grill. Before doing this, I drove a 37-mile RT course I've used before to check on fuel economy and other car issues. I repeated the course this morning, attempting to recreate conditions as much as possible.

For consistency sake, I made certain I had 6 bars showing as SOC on the HV battery Thursday night and Friday night. This allowed me to have a cold-soaked ICE (went down to freezing each night) to start the runs each morning. Friday morning I started when the temp was already up to 41 F. Saturday I couldn't wait so long, and I started with a temp at 39 F. In both cases, the temp had reached a balmy 43 F by the time I finished. The SOC also ended at 6 bars each day.

I ran 36 miles down, stopped and turned of the car and went inside. Friday I waited only 8 minutes before starting the return trip. Saturday (today) I took a bit more time and didn't start the return trip until I had been inside for 13 minutes. Because the sun was shining brightly both mornings, I didn't run the heat either morning.

That's about as much as I could do for consistency purposes. I couldn't control traffic or the weather (or the stop lights). I had a bit more traffic on Friday, but not enough to make any real difference. The only thing that really could have made a difference is that the wind picked up on my return trip Saturday. This created a noticeable headwind, and I believe it did cause lower mileage. It wasn't present an hour earlier, so I didn't have a tailwind on the out-bound journey.

I believe the grill blocking is at least partly responsible for increasing the fuel economy on the first part of the trip. Friday (NO grill blocking) the FE for the first 37 miles was 52.1 MPG (from the MFD), while under the same conditions the next morning, Saturday, the FE for the same exact trip was 56.5 MPG. That is slightly more than an 8% increase, so it is enough to have some statistical relevance. It was only one pair of data points.

The return trip is a bit more problemmatic for comparison purposes, because of the headwind on the second day (Saturday). Even so, here are the numbers: For Friday (NO grill blocking) the FE for the second 37 miles was 56.1 MPG, while the same miles covered Saturday (with the final 20+ into a freshening headwind) showed 54.9. This is a decrease of just over 2% -- perhaps not enough to have statistical relevance. Again, it is just one pair of data points, and the comparison is taxed due to the headwind.

Overall fuel economy changed from 54.1 MPG RT for Friday (NO grill blocking) to 55.7 MPG RT for Saturday. It is hard for me to say the 3% increase has that much statistical value. If I could find out the loss from the headwind and subtract it . . ..

I do believe this little "test" shows the ICE warms up more quickly with the grill blocking in place -- as evidenced by the comparison of the first leg numbers for each day. If I could get a 3%-5% increase in FE just from using pipe insulation, I think it would be worth the cost. One third of the year for grill blocking, when I drive 18,000 miles per year, means I would use close to one tank's volume less of gas each winter at the 5% end. In any event, I project the cost savings at between $18.50 and $30.30. That's more than I paid for the insulation. Because prep took at least 3 minutes and installation nearly 2 more, it didn't take a bite out of my day.

Regardless, I like the idea of having the cabin warm up a bit faster with the insulation helping to keep the ICE heat for the ICE (and for me).

 

Well I blocked up my lower grill Sunday afternoon, finally caught a break in the rain we had over the weekend.
I ended up needing only 3 1/2 pieces since my front license plate covers the middle of the upper slot, actually it blocks the center of the upper 2 slots but I was able to get a full piece in the second slot it didn't fully cover it and then tucked in under the plate holder on the top slot.

It's really too early to say anything, but I have to say, I got the best mpg on the way home I have gotten on my commute and I got my best morning mpg on my way in today.
Of course it was a little warmer today, it has warmed up like 15 degrees this week over last week.
It definitely isn't hurting anything having it done.
Thanks to everyone who contributed to this thread, best $2.97 I have spent on the car yet.

 

The return on that expense makes it a no-brainer.

 

John.. I am in MN as well (Twin Cities area). Do you block upper and lower this time of year or just lower?

 

Just the lower.

 

John,

Twin cities guy here too. I just blocked my lower grille, question for you is do you run scanguage or is it safe to run lower grille block only w/o scngauge with temps the way they are now?

 

You should be fine unless you have an extremely warm day or are running the engine very hard for very long.