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

Depends on your driving style and route(s). However, I will be removing my block when the temps remain in the lower 40's. I could stretch that to the upper 40's but I'll simply keep an eye on it. The only manifestation for too much heat would be the radiator fan coming on and staying on longer.

 

We're getting days in the low 70s now, but still 50s in the morning. I wasn't even going to think about removing the blocking until the first day I felt inclined to use the air conditioning or the first day I really needed to put the window shade up. As I rarely (almost never) drive much more than 30 minutes at a time, I'm not terribly worried about over-heating.

 

I think I need one of these.

 

The factory Prius C does not have a temperature Gage on the instrument panel. HOW DO YOU MAKE SURE BY BLOCKING THE FRONT AIR INPUT YOU WILL NOT OVER HEAT AND DAMAGE THE ENGINE? I live in the desert and the winter temp. never gets below 28 F. Can I safely block my front air intake and not over heat my engine? If so, how much area should I block?

,

 

anyone wonder why the Ford Focus SFE (super fuel efficiency) model incorporates electronically controled louvers to control air flow thru the front grill?

the reduced warm up time is part of the reason your efficiency improved. the rest is due to lower air friction since the air no longer gets trapped in the grill disrupting the air flow around the car

but reducing warmup time is essential and really noticable in shorter trips. I experimented with my Prius on this seeing mpgs in the 20's for one way trips under 3 miles

 

Okay, I am baffled on why you are seeing such an improvement in gas mileage.

Part if from less time the engine needs to run to keep warm.

Part is from less air flow friction.

The negative is the voltage converter runs hotter and hence, will fail sooner.

Are there any other engineering reasons why Toyota did not do this?

 

I have my upper grill 100% blocked and my lower grill 60% blocked and the inverter temp never get close to +20 over ambient temp which is within the expectable range. This is with the outside temp as warm as 65-70 degrees. The inverter radiator is located at the bottom of the ICE radiator.

 

Thanks for the info sph101....so why doesn't toyota do this for all of its vehicles? It would be a dynamic blocker, depending on how cold it is outside, how warm the engine is, it would dynamically adjust to maximize the fuel economy?

 

My guess is cost and customer demand, Toyota does not need the gimicks to sell the cars.

 

They are starting to get real pressure from honda...it will be intersting to see what they do on the 2015 refresh

 

I kept my lower grill blocked all summer. The scangauge was good so never undid the block.

 

What part of the grill I can block all year long?

 

Measureable and material improvement in fuel economy isn't a gimmick!

SCH-I535 ? 4

 

Depends on where you live and how hot you get.

 

I wouldn't grill block any amount if using AC to cool the cabin: the cooling efficiency depends on open grill.

 

Most cars do best MPG at operation/warm up temperature. It takes the gas engine a little longer in a Prius/Prius C to warm up because it is not being used. However it is a small engine and small engines are worked more and warm up faster then larger engines. This is just a guess on my part.

 

If you want another choice try the temperature controlled foundation vents placed inside the grill.
That actually looks very good. No, we don't have comparisons yet. but doi notice the car acts more aero.

 

I let the heater turn on whenever the computer decides and usually have it set to 73-75F. Usually the computer begins to slowly crank up the fan after a few minutes.

When the ambient temps are in the low 30's my trip to work mpg is usually around 53-54. On normal summer days it is 60-62mpg with A/C on.

Keep in mind also that the air specific volume goes from 14.0 to 14.5 cubic ft/lb when in the 85-90F range to 12.0 to 12.5 cubic ft/lb in the 30-35F range. That nearly 20% density increase will add to the drag on our diminutive C's drivetrain during the winter months if you are at highway speeds like I am. The thermal effects of cold weather have a greater mpg detrimental impact I am sure, but the increased drag will have its effects too.