Finally got to pull a grill block today!

[efusco]

I use a CAN-View

[DaveinOlyWA]

wow... wish the weather was good enough to pull some of mine. had a few days in the 70's and actually had water temps hit 210º once, but that lasted a day...its like 55 right now...

[Shawn Clark]

Pulled mine this past weekend. Hated to do so as the mileage just kept going up...56 mpg on short trips with highway/interstate interspersed. Mileage is trending back toward 53 since I pulled the blocks. It's too bad that Toyota doesn't have grill slat thermostat controls for the coolant and inverter. This would improve warm up and mileage on short trips even in warm weather.

The grill blocks made a big difference this winter. Earlier this fall/winter without blocking when the temps dipped below 30 F I observed mileage on various trips at those temps hitting around 42 mpg ave.--and only days before I was hitting 50 mpg on the same routes with temps in the 50's. After completing the grill block of all but the bottom-most slot, mileage improved to the high 40's again. The last two tanks with the grill blocked were 50 mpg.

[efusco]

Originally Posted by Shawn Clark

Pulled mine this past weekend. Hated to do so as the mileage just kept going up...56 mpg on short trips with highway/interstate interspersed. Mileage is trending back toward 53 since I pulled the blocks. It's too bad that Toyota doesn't have grill slat thermostat controls for the coolant and inverter. This would improve warm up and mileage on short trips even in warm weather.

The grill blocks made a big difference this winter. Earlier this fall/winter without blocking when the temps dipped below 30 F I observed mileage on various trips at those temps hitting around 42 mpg ave.--and only days before I was hitting 50 mpg on the same routes with temps in the 50's. After completing the grill block of all but the bottom-most slot, mileage improved to the high 40's again. The last two tanks with the grill blocked were 50 mpg.

Agreed, an electronically/thermostatically controlled grill block/air redirect system may be the single most dramatic thing they could do for improving FE without the owner having to plug in or do something else "actively" to achive that result (ie. EBH). It shouldn't be that expensive, heavy or complex either. And if it were done really slick it could even improve the Cd if they smooth the front end when closed and then just tip open as needed to allow in air to cool the ICE/Inverters.

[rpg51]

I was 100% blocked until this heat wave. I have to say, at $2 a gallon the economic benefit of the block seems pretty minimal - might be outweighed by the risk of damage if you are not monitoring temps and you forget to pull it when the weather turns hot all of a sudden like it did last weekend. I know that is heresy around here.

[Mike Dimmick]

Originally Posted by efusco

Agreed, an electronically/thermostatically controlled grill block/air redirect system may be the single most dramatic thing they could do for improving FE without the owner having to plug in or do something else "actively" to achive that result (ie. EBH). It shouldn't be that expensive, heavy or complex either. And if it were done really slick it could even improve the Cd if they smooth the front end when closed and then just tip open as needed to allow in air to cool the ICE/Inverters.

BMW already do automatic grille blocking louvres - they call it 'Active Aerodynamics' as part of their EfficientDynamics theme. It may be patent-encumbered.

The exhaust heat recirculation on the new Prius will help a bit, but it won't stop the engine being cooled unnecessarily when it's off.

[efusco]

Originally Posted by rpg51

I was 100% blocked until this heat wave. I have to say, at $2 a gallon the economic benefit of the block seems pretty minimal - might be outweighed by the risk of damage if you are not monitoring temps and you forget to pull it when the weather turns hot all of a sudden like it did last weekend. I know that is heresy around here.

It's not heresy, just uninformed. We've posted multiple times in the various articles and threads on grill blocking what we consider safe...and trust me, these are VERY conservative. I was still fully blocked up to mid-70sF and showing very safe temps with my CAN-View for my inverters and the ICE. My recommendations for those without the ability to monitor those temps is to remove ALL blocks by 50F. I'm still blocked in all but 2 lower slats with temps in the 80s and showing very safe operating temps.

I'm also getting ~75mpg 200+ miles into this tank. So if that's minimal benefit to you, so be it. To me it's fantastic and achieves what I'm shooting for.

[Shawn Clark]

Originally Posted by Mike Dimmick

BMW already do automatic grille blocking louvres - they call it 'Active Aerodynamics' as part of their EfficientDynamics theme. It may be patent-encumbered.

That's a patent fight that should be easy to win. It's hardly novel. WWII aircraft of various types (and likely before) had similar arrangements. Open up the ports to cool the engine, close them for speed.

[DaveinOlyWA]

Originally Posted by rpg51

I was 100% blocked until this heat wave. I have to say, at $2 a gallon the economic benefit of the block seems pretty minimal - might be outweighed by the risk of damage if you are not monitoring temps and you forget to pull it when the weather turns hot all of a sudden like it did last weekend. I know that is heresy around here.

its too bad that more people cannot apply your alarmist stand to the possibility of Global Climate Change

[Shawn Clark]

The problem as I see it is the inverter. Since I have no way to monitor the inverter temp (haven't bothered with the Scangauge since my understanding is that it doesn't report it either) I have to unblock everything when the outside temps start pressing 80 F. Plus if the wife is driving she's not going to reliably watch/catch things like that, so even with a gauge I would still have to unblock it for her.

I'm not really worried about engine coolant as fans and such will begin running to take care of that even though I can't monitor it directly at present. However, the inverter is a black box to me...

This should be done automatically with an electronic control scheme and shutters. Various temp. points could be used, much like the present limitations on stage operation of the hybrid system.