GM Testing What Ecomodders already know: The Grille Block

[markemmanuel]

I finished reading a short article at Automotive News about GM testing new grille blocks to improve fuel economy on their truck. Their twist is developing movable slats, something that many of us have thought about doing in our cars instead of non movable grille block. Well, here's the story link.

http://www.autonews.com/apps/pbcs.dl...302159901/1113

[Daox]

$60-100 seems a bit high IMO. I'd have to imagine it can be done quite a bit cheaper. Even so, the mileage increase from blocking those gigantic grills on the trucks will pay for it in no time.

[MadisonMPG]

OMG they'll probably look into air dams next! *gasp*

[markemmanuel]

They probably overestimated the price of the grille block system.

I think people would actually buy an aftermarket system if it works seamlessly with their car for under $120.00. If there are any innovative ecomodders out there that's willing to get together to design, produce, and sell these grille blocks, I think they'll make decent cash from it.

[MetroMPG]

We already know that it's going to help MPG.

The question GM is looking to answer is whether it's going to help enough on the EPA test cycles to justify it on some GM bean counter's spreadsheet. This is probably more about meeting CAFE requirements, not providing better MPG to people in the real world.

Unfortunately, precisely ZERO of the EPA test cycles measure fuel economy over long distances at 70+ mph, like much of America travels.

[NeilBlanchard]

They do say that it is an active grill block, that changes based on conditions. But of course a "passive" grill block would cost a lot less and be a lot less expensive, and probably save as much fuel.

Why stop with the trucks, GM?

[Frank Lee]

Cost to GM $60-$100? I don't see how.

Cost to consumer an extra hundred, I can see that.

[gascort]

Don't the EPA tests assume aerodynamic drag based on numbers that are furnished by the automakers? I think this could affect their wind tunnel numbers that they furnish, therefore affecting EPA highway MPG.
That said, I am very suspect of the Equinox claims of 31 highway; I wonder if they fudged their aero numbers a bit. We'll see by next year what drivers get.

[orange4boy]

Cost to GM $60-$100? I don't see how.

Cost to consumer an extra hundred, I can see that.

That would be GM for sure.

The VW beetle had active cooling via a little bi-metallic bellows that would close flaps on the fan shroud when the engine was cool and open them when hot. This would allow quicker warmups and lower fan load on the engine while warming up. Not quite the same idea but if they could do it on the low cost Beetle in 1970...

At GM, we recycle everything, including old ideas... and take the credit... and charge you extra.

Actually it will be quite expensive to develop this ground breaking new tehnology... They have to spend a lot of time designing it to break right after the warranty expires.

[MetroMPG]

Originally Posted by gascort

Don't the EPA tests assume aerodynamic drag based on numbers that are furnished by the automakers?

They do, but the EPA's highway test cycle has an average speed of something like 48 MPH. Meaning the fuel economy benefit of aero mods for the purposes of CAFE is diluted.

That 48 mph average makes it easier for the bean counters to say "nay" than "yea" when it comes to cost/benefit. The % impact on EPA tested MPG is going to be less than in the real world, where people drive 70+ mph all day long.