Boy this car likes the warmth I Blocked front grille to experiment

Send some of that hot weather up here! It's been below freezing overnight here for the past week or so.

 

No, thank you! We'll be getting freezing temperatures here soon enough and I'd rather hold on to what we've got for as long as possible.

 

Dan,

Since you are in a much colder climate than I, you might consider using some of the leftover bits to do the upper portion as well. Though I don't know if the whole "where is the inverter and will blocking it be an issue" question was ever answered or not.

 

I have my grill 100% blocked both upper and lower. My scan guage never showed the engine temp above 190 and after the trip I opened the hood and checked the inverter and it was barely warm to the touch. Outside temp was 51 degrees. It was mostly stop and go driving between 35 and 45 mph. I have done this several times and the inverter has never been hot.

 

Thanks, sph101!

I guess I'll go ahead and do my uppers before it gets too much colder here.

 

A 3rd gen Prius expert advises against blocking upper completely, due to inverter radiator. You might be able to tell this item's location on C: as far as I know, it's the only diminutive radiator. The AC and reg coolant rad's are full size.

Another tip off would be hoses leading back to the inverter .

 

Silly question, but will they come off when you go through a car wash or is it wise to remove them each time?

 

That is the reason I did mine in long strips. They're quite sturdily held in place. I was afraid to do smaller pieces for fear of them gradually working free...not that a little foam will hurt anyone, but more litter defeating the purpose. I imagine they may pop loose if you do small pieces especially if it is a touchless car wash...as the jets are quite powerful.

 

Ok, I will do the lower this weekend and see how it works. I have a temp gauge in Ultra Gauge to watch. My mileage has fallen on these mid 30 mornings. I will probably block the entire thing before I quit.
Thanks for the responses to this thread.
Dan

 

You can hold them on with zip ties. I started with this method, then switched to velcro ties. More convenient to add/subtract. Here's one source:


Velcro® Plant Tie - Lee Valley Tools

 

My daily commute is 20 miles and my PC's MPG was about 63 when the weather was warmer. It has dropped significantly to 55 to 57 because of the cooler weather. So, I visited this forum and hoping to get some tips about increasing MPG during winter time. Saw this thread and went to Lowes after work. I bought some 1/2" pipe insulation for $.97 each. Installed it on the lower grille this morning. I did not block 100% of the lower grille. The top and bottom openings are narrower and I could not keep the insulation in place. Did not have time for the top grille. However, I could see improvement already even though I only block part of the lower grille. Today's temperature was the same as yesterday. I got about 55 MPG yesterday and I was able to get 59.9 MPG today! This mod is really easy to do and the cost is minimal. Highly recommended!

 

Try straddling the horizontal grill components with the slit in the pipe insulation. You will need to cut vertical slits, but only about 1/2 way through,to match up with the vertical grill pieces. I have done this and it works fine on my regular Prius. No need for tie wraps or velcro!

 

I recently saw another post where that stuff was available at Lowes or Home Depot for about the same price, don't remember which. That will help us USAians, not sure about our friends in the GWN

 

Today should be a great test of my full lower grill blocking. The temp is 50, the winds are high, and I will be traveling my usual route but with a passenger for the first half of the journey and a passenger and a car full of groceries for the trip back. Will report later today!

 

Okay, it would be snowing a few minutes later, so judge temperature by that. Fully loaded with groceries, two flats of water, and a passenger. 9.7 mile journey from cold start, 79.1 MPG at end of trip. Cold, windy, wet.

 

This morning with an outside temperature of 35 degrees (!!), I managed to get 50.2 MPG on the drive to work.

 

Scangauge has an Xgauge for the inverter temp. I've loaded it on mine and have been watching it over the last bunch of days. Inverter coolant temp stays 5-10* over outside temp. It sometimes goes a bit higher, but I've not seen it over 20* higher than outside temp.

I haven't blocked anything off in the front, so don't know how it would be affected or what would be considered a problem.

As for the car wash concerns, I would number them on the back side in magic marker or Sharpie. That way they can be quickly replaced in the proper order. Surely it wouldn't take more than 45 seconds to remove them all before a wash. I usually wash after a fill so I could remove them while the gas is going in. They could be replaced quickly enough, and in the proper place, afterwards.

Just my thoughts on that. I probably ought to try it out. It's been in the upper 20's in the mornings. The C is surely a cold blooded beastie.

 

Here is a picture of my grill blocking.. my aim is even but reduced air flow. Temps are 30-50F here now. With this (lets call it 50% overall) grill blocking I am back to fair weather mpgs and the heater is producing noticeably warmer air. With only 50% upper and lower blocked I am not worried about wherever the inverter radiator is or whether or not my significant other will notice the idiot light if it comes on.

Thanks sph101 for doing the scan guage work! I'm using your results to claim my design has a very large margin of safety built in.

 

Your grill blocking design kind of reminds me of the musical note grid used in Close Encounters of the Third Kind.

Start watching at 5:35 min in!