Stuffed foam in grill - MPG update

[swingdj]

Following the suggestion of several posts on this site, about three weeks ago I walked out of my local big box home improvement store with $2.08 less in my wallet and two pieces of six-foot long foam pipe wrap / insullation in my hands. I carefully measured my front grill, including the veritical support brackets and cut pieces to completely fill in the upper grill. I did create V-shaped notches to nest the foam around the vertical supports -- a must to get the foam packed in tighter. I left the lower grill alone.

 

I picked up my '14 HiTi on 12/31/13, so I've only driven it in freezing cold weather, mostly -5* to 25* F during the past seven weeks, about 1,700 miles total.

 

Before the foam, I was averaging about 38-39 MPG (going off the vehicle readout) in cold weather. On days of similar temperature, I'm getting 40-42 MPG. I never timed it before, but I believe it's warming up a little quicker than before, which is probably why I'm getting the improved numbers. I have hit 42-45 with the foam when it's 30* to 40* F outside, but we didn't have that "warm" of weather before I put the foam in.

I would definitely recommend this to anyone who's driving in a colder climate. It's a few dollars and about 60 minutes of work. Just remember to take it out once the temps start getting up into the 50s!

[billford]

I was thinking of doing the same.

 

Could you post some pictures please?

[hybridbear]

I was thinking of doing the same.

 

Could you post some pictures please?

Our FFH

 

Our Prius

 

My parents' C-Max Energi

[KLH]

I have the plastic grill cover and see very similar improvements in gas mileage. The one downside is that I forget that it's there... and have gone through a carwash only to see the grill cover spin off! (LOL!)

 

Anyways, my question is - for the insulation approach carwash proof?

[swingdj]

I have the plastic grill cover and see very similar improvements in gas mileage. The one downside is that I forget that it's there... and have gone through a carwash only to see the grill cover spin off! (LOL!)

 

Anyways, my question is - for the insulation approach carwash proof?

 

I am going to ASSume it is! I'll let you all know. If it is not, then I'll be back to the big box store. Good thing I'm not a car wash nut.

[hybridbear]

We have had no issues with the foam insulation coming off in the car wash. I did lose one piece going 70 MPH on the freeway. It's important to make sure that the foam pieces are firmly stuck in the grille and not sticking out on the sides.

[acdii]

I would have thought by now that I would have lost at least one of the pieces I stuck in the lower grill, but even after a car wash they are still firmly in place.

[billford]

I just installed some foam into the upper grill, similar to the posted picture, will monitor the mpg and temperature over the next few weeks to see if it makes a difference.

 

I don't think its a good idea to block the lower grill. There is 2 radiators in that location, the trans and inverter coolers. The lower part of the a/c condenser is also in that area. There's no real way to monitor the temperatures of those systems when the lower grill is blocked, so its possible to overheat those systems.

 

For the upper grill blocking, you can monitor the engine temperature in the "my view" screen in case it gets to hot.

 

[hybridbear]

I just installed some foam into the upper grill, similar to the posted picture, will monitor the mpg and temperature over the next few weeks to see if it makes a difference.

 

I don't think its a good idea to block the lower grill. There is 2 radiators in that location, the trans and inverter coolers. The lower part of the a/c condenser is also in that area. There's no real way to monitor the temperatures of those systems when the lower grill is blocked, so its possible to overheat those systems.

 

For the upper grill blocking, you can monitor the engine temperature in the "my view" screen in case it gets to hot.

I am monitoring temps with my Torque app. I have been short on time and thus haven't started a thread to talk about all my observations, but so far the temps of the Gen Inverter & Traction Motor Inverter have stayed mostly under 120F. This is on trips where the car starts out warm from being underground so their starting temps have been around 60-65F. When their starting temps are closer to ambient temps (<15F) they stay much cooler for longer. As I gather more data I will report more. I will use the temp monitoring to figure out when to remove the block from the lower grille. My goal is to keep their temps under 100F as much as possible. I'm also curious to see how warm they get in the summer when the outside temp is 90+F. My guess is that they get a lot hotter in summer with full airflow than they get in the winter with grille blocking. There are no fans to pull air across those radiators.

 

I do not have data to monitor the temps of the actual electric motors, but from my observations with the Prius where I can monitor both inverter temps and motor temps and the temp of the coolant for that loop, the inverters are the hottest part of the system. The electric motors themselves stay much cooler and the coolant in that system stays much cooler than the inverters even with100% grille blocking on the Prius.

 

I have every square centimeter of airflow into the engine compartment blocked in the FFH, both grilles and the small lower slit in the bumper.

Edited February 27, 2014 by hybridbear

[ptjones]

I am monitoring temps with my Torque app. I have been short on time and thus haven't started a thread to talk about all my observations, but so far the temps of the Gen Inverter & Traction Motor Inverter have stayed mostly under 120F. This is on trips where the car starts out warm from being underground so their starting temps have been around 60-65F. When their starting temps are closer to ambient temps (<15F) they stay much cooler for longer. As I gather more data I will report more. I will use the temp monitoring to figure out when to remove the block from the lower grille. My goal is to keep their temps under 100F as much as possible. I'm also curious to see how warm they get in the summer when the outside temp is 90+F. My guess is that they get a lot hotter in summer with full airflow than they get in the winter with grille blocking. There are no fans to pull air across those radiators.

 

I do not have data to monitor the temps of the actual electric motors, but from my observations with the Prius where I can monitor both inverter temps and motor temps and the temp of the coolant for that loop, the inverters are the hottest part of the system. The electric motors themselves stay much cooler and the coolant in that system stays much cooler than the inverters even with100% grille blocking on the Prius.

 

I have every square centimeter of airflow into the engine compartment blocked in the FFH, both grilles and the small lower slit in the bumper.

I was unaware that there was an out put for Gen Inverter & Traction Motor. It would be nice to pick that up on the ScanGauge.

 

Paul

[hybridbear]

I was unaware that there was an out put for Gen Inverter & Traction Motor. It would be nice to pick that up on the ScanGauge.

 

Paul

Unfortunately, the XGauge codes published for those functions don't work. But an Energi owner converted the XGauge codes to Torque PIDs and they work in Torque.

[swingdj]

Here are pics of my top grill with the foam installed.