First Morning with a Blocked Grill

:welcome:

 

Hi Snead C,

I just made an online calculation with miles, kilometers, gallons and liters.
My Toyota Auris Hybrid should be abled to have a milage of 61 p gallon, according to what Toyota claims.
It is therefore slightly more fuell efficient than a Prius III.
So far I have just 2000 miles on my display, so it is not broken in yet.
So far my grand total average is about 45 miles p. gallon, including some severe wintery conditions (during half a tank about 39 miles p. gallon).
When I look at the display, my average is 4,9 liters per 100 kilometer, converted that`s 48 miles p. gallon, or in real life 45.
Greetings,

Arnold



As soon as I wil have to fill it up again, I can see how much a difference my grill blocking has made.

 

Another side-effect of grill blocking is the aerodynamic improvement. Having air not go through the engine compartment helps!

 

Yesterday I filled her up again.
Now I can see the impact of grill blocking, because I drove 786,1 kilometers on 38,88 liters of gas, and I never reached these figures before.
Converted that was 488,56 miles, and 10,508 gallons, so 46,49 mpg.
This is an improvement of 0,9 mpg.
So far I drove 2380 miles with my Toyota Auris Hybrid.

 

I'm glad to see you are successful. Just a reminder..remember to remove the blocks as temps warm up. Without a guage you would be wise to remove them when temps are above 50f.
:rockon:

 

With my gen 3, and no ScanGauge to show coolant temp, I've been using no blocking of upper grill (due to concern that Inverter Coolant Radiator is in this zone, and on the lower grill:

Under 5 degrees centigrade: 100% grill block (2 pipe insulation tubes, full width)

5 to 10 degrees: 50% block (remove the lower tube)

Above 10 degrees: no block

Just playing it safe (I hope) with no coolant temp feedback.

 

The nice thing about the Toyota Auris Hybrid is its display, because it also monitors the temperature of the ICE!
I have no scangauge, but I keep an eye on the temperature indication, it consists of a number of small horizontal lines besides a symbol of a thermometer.
Because I make short trips of up to about 26 miles, I think I`ll be safe at ambient temperatures of up to 55f.
Above this temperature I`ll remove the cover of the upper grill, to prevent heating up the inverter and keep the bottom closed.
(The drivetrain of the Auris Hybrid is identical to the one of the Prius III)
On the freeway I drive at moderate speeds of 60mph up to 75mph maximum.

 

I blocked upper grills yesterday (on Prius II). The outside temperature was 28 C (noon time). I had to drive after 4 hours, and noticed that engine was still little warm. The Car jump into S4 mode fairly quickly.

Even today morning , It performed slightly better and jump to S4 during 4km trip. I usually will not get S4 during this short 4km trip.

I think this will have a greater effect when I am doing several short trips (specially during weekends where we need to goto Church, Marketing etc).

As we have tropical whether, there is no great heat loss, but starting FE is always a problem. Grill blocking will have a kind of positive effect.

I blocked only the upper part as Hybrid cooling system get cooled from lower side.

Has anyone done grill clocking for Prius II during summer / hot weather ?

 

Block heater + blocked grill is a killer combo. I'm currently getting 62 MPG combined city/hwy now that temps are averaging between 45-57F (with a little pulse/n/glide and hard LRR tires). Amazing for me since I started out getting 34-40mpg in winter when I bought the car.

 

Today morning commute was as good as I thought. Certainly it helped to reach S3 quickly and ICE was on only for short durations. However It took a while to reach S4. The outside temp was 25C and it was humid (We had heavy rain), compare with previous day (28C Sunny) outside was much cooler.

May be I will try to cover lower grill 50% as well.

 

I decided to remove the grill block as it looks like affecting the afternoon FE. Basically I was getting lower FE while coming back home. One pattern I notice is I was getting very low FE during the heavy traffic portion, much lower than earlier. Also I noticed that Battery is depleting at a higher rate. That actually casing the ICE to come.

One reason may be that FAN is working to cool down the Engine which might drain the battery faster.

There is no need for grill block for the afternoon trip, but it would have helped the morning trip.

 

I removed one grill (lower) block. I did not travel longer trip, but three small trips. Looks like it worked better. Lower grill is not blocked at all.

Hope this mod will be OK for daily trips. Keep you inform

 

If temps are above 50 degrees it may be time to "take the covers off"

 

I would have thought it might be over 50 CELCIUS in Columbo, and I bet you're talking F. I wouldn't have thought grill blocking in Sri Lanka was necessary.

 

F...doesn't everybody follow US customs ? ;-)

 

Colombo temp in the morning is 26-27C and afternoons 32-33C (79-81 F and 89-91 F).

This is not necessary for afternoon period, but I thought there is a positive effect in the morning.

 

There may be a positive effect but without good air flow around engine compartment during warm to hot weather the drive components could over heat. A scan guage (there's a new model coming out that's around $100 US) should be used to monitor coolant/engine temps to keep your engine safe. Without temperature monitoring you might save a few ounces of gas per gal but ultimately severely damage your drivetrain.
Without blocking yesterday I observed 60 mpg yesterday...72 F.,flat terrain, 42 mph, no AC, and light traffic and load. Not typical but good enough without competition.
Gooooo Prius :cheer2:

 

Today I removed block between hood cover and the body (It was blocked in addition to grill blocks). Looks like it is more suitable as there is a slight improvement on Mileage. ( I was comparing the 5 minute bars. )

I will run this for another day or two. As the outside temp is high (33C) A/C is running at 27C. This will drain the Battery fast. I also assume that Engine fan might come on if A/C is running high.

 

Now I can confirm that for current heat, engine grill block will affect negatively. Although I do not have any scanner/meter to monitor, the consumption graph itself give a clue. When the heat is two much and maintaining a average speed, the bars are at same level. However I noticed that before the grill block, I could see some variation. When I removed the grill block, the variation again appear.

However when the outside temperature is lower than 28 C, I could see slight improvement in MPG (km/l) as it goes to S4 quickly and try to run on the battery even at 55 km/h.

This experience has help me to monitor consumption patterns more carefully as we could improve mileage even looking at the display, specially if you are taking the same route every day.