Grill block on/off experiment: 71 mpg v. 62 mpg

Gotcha So in the winter, I can use interior heating as long as my temp stays above 168F with no reduction in mpg?

 

Engine cooling fan speed is also a function of coolant temperature, so at some point that matters too.

 

OK, you asked for it, you got it:
Automatic grill blocks, "Eco-Flaps" for Gen II and Gel III:

rescatandoenergia Google Spanish2English Translation

Cost? $775.65 USD + S&H

Original links:
ECO-FLAPS HV, ConvierteTuHi­brido

ECOFLAPS: Prueba de larga duración (Verano)

 

I have been thinking about making something like those but not auto/electronic. A simple hinged louver on the inside of the lower grill would be perfect.

 

Yep- Just a LARGE vent control set-up like the vents in the passenger compartment.

 

Way back when: Volvos used to have a grill block that worked like a roller window shade with a pull cable on the dashboard.

 

I gotta admit that the pic of that monkey smoking the cigarette keeps me from taking you too seriously - it also makes me laugh out loud every time I see it!

 

Affirmative.

But coolant temperature can change rapidly in the winter, so
be mindful how you use interior heating in stop and go traffic
and when you are doing P&G sessions - that is when you are
attempting to get better FE by cycling the gas engine
on and off. However, on the superhighway when the gas
engine is always running thats when you are either using
CC or DWL (and you are not drafting) using interior heating
is less of a problem.

 

What r u guys using to block off the front of the grill? I live about 40 west of Chicago & in the winter my MPG goes to about 42 where in the summer it is about 50- 52 MPG. Give me some help. Thanks Ron
P.S. I have a 2010 prius

 

There are tons of threads on grill blocking, just search "grill blocking" in the white search box at the top of this page. I used 3/4 in pipe insulation from walmart, cost ~$2.50. I just used 2 pieces for the top, cutting a bit off each so they fit snugly. And I cut bottom pieces 7.5" to go in the slots. It almost filled both grills. I know you have a gen III and I think your grill is a bit different but you can probably do something similar to mine. The benefit of this install is I can easily take pieces out and they've seemed to stay well not to mention the benefits of grill block .

 

Agreed but also pay attention to your temps if you have the opportunity for long gliding or coasting sessions on your commute. There are a few points along my commute that grill blocking helps me retain engine heat during a very long coast or glide. Without the grill blocking I lose heat faster and my engine must turn on sooner which lowers my mpg. In those cases grill blocking is very helpful even at highway speeds. It may also help to turn off the heater prior to hitting those spots?

 

Oh no.. you killed the monkey!

I actually liked it alot b/c the pot smoking monkey alone with depth of his posts and homage to XS-650 gave him dimension. Now it is plain vanilla.. bring it back! the last thing you wanna do is argue with someone with amputated sense of humor.

When I get tired of Marley I'd go with Monty Python images..


:focus:

 

I live in Wisconsin and just did the Grill blocking with 3/4 inch foam pipe insulator. I did almost full block on the bottom and 75% on the top. My questions is should I remove the grill blocks in the summer or am I safe with keeping them on?

 

My advice/suggestion would be to remove them in the hot Summer - after all -- We DO get some hot weather even up here.

 

If you have a scanguage or OBDII adapter/sw combo you can monitor your coolant temperature. Any temp above 168F is no benefit for your mpg, but allows you to run the cabin heater when you want it. A coolant temp > 205F is dangerous. There isn't a benefit to keeping your grills' blocked in the summer, only the risk of harming your Pri.

~Lots of credit to others (but I'm learning)

 

AC performance is not going to be helped by a blocked grill. I'd take it out going into summer whenever you start using AC for actual cooling, as opposed to dehumidifying, in cooler weather.

 

Due to a cool local summer most of my grill blocking did not get removed until early September, and was reinstalled merely two weeks later. But this is not at all safe without an engine monitor such as ScanGauge. Most of the country was far too warm this year to have survived this.

 

Thanks guys I will remove them once the temperature starts to rise which wont be for awhile here in Wisky. I also inflated my front tires yesterday to 41 psi and the back to 40 psi and have already started to see an increase in my mpg. When this tank of gas is gone I cant wait to see what my new mpg is. I was only getting 39 mpg so I am hoping for closer to 48 =) When I checked my tire pressure they were only at 30 psi stupid used car dealership lol. Everyone here has been incredible in helping get my car to be as efficient as possible!

 

Also would be nice if someone made a grill block kit that could be removed and reinstalled that looked good on the car. The way I did mine dosent really look "bad" but it dosent look good either.

 

Now see, I appreciate the effort there and all. But every time I think about this automatic louvre idea I have an image in mind of them being flush with the bumper cover when closed. Cleaner look and much more aero. Plus the open/close action would be more visible for wow factor. ;-)

- D