Grill block on a Silverado

[darcane]

Well, I was asking for mileage rather than miles.

I was at about 15-16 when I started too. I'm typically getting just over 20 now. Definately report what you get on your next tank. Actually, start a fuel log too. That's good for really seeing how it's doing.

[aerohead]

Originally Posted by darcane

Found it, thanks Phil.

It doesn't quantify each mod individually, so it's hard to say how much it affects mileage. My next step is blocking the area between the frame and the body between the wheels (#3 in that image).

I want to get rid of the canopy and get a tonneau cover instead, but that's a tough sell with my wife. She finds the canopy too useful even though I find that it gets in the way.

I went back over the Crisis Fighter Pinto article from back in 1974.Here are some data Car and Driver got from their mods:
*low airdam ( 2-inch ground clearance)= 10% delta Cd / 6.16% + mpg @ 70 mph
* complete grille block with airdam = 22.831% delta Cd/13.69% + mpg
*compromise grille block with airdam = 15.98% delta Cd/9.59% + mpg
* grille block alone = 4.56% delta Cd/ 2.739% + mpg
* 2-blade cooling fan vs 4-blade = 0.5 mpg= 5.7% delta Cd/3.4% + mpg
* complete fan removal= 1.0 mpg= 14% delta Cd/ 6.84% + mpg

[apc]

just filled up this morning at the same time, same station, same pump. 18.92mpg

that's a 20% improvement.

me = happy

[FastPlastic]

Originally Posted by apc

just filled up this morning at the same time, same station, same pump. 18.92mpg

that's a 20% improvement.

me = happy

I'll give that . Awesome job on the mods, clean and smooth. I find it amazing how big of a difference we are able to make with some fairly simple mods that really don't even alter the look of the vehicle. Yet the car companies spend millions to squeeze only a few MPG's out of the new model.

[apc]

I'm fairly sure the majority of the gains have been from inflating the tires past mfg spec and changes in driving practices, but no doubt the aero mods have contributed as well.

indeed car mfgs are pretty pathetic, although it isn't entirely their fault. a number of factors, largely political but some technical and a few capital, work against the widespread improvement of fuel efficiency at the retail level. that just means the ecomodder movement must grow!

[darcane]

Well, as summer heats up, I'm starting to notice my temps creeping up. With no grill block, my trucks stays at a pretty consistent 192°F. It's getting up into the 200-210°F range now with ambient temps around 80°F. If that keeps creeping up, I may have to pull off part of the block.

[apc]

wow. my dash gauge still hasn't budged and there's been a few days where air temps have approached 100. I have yet to extend my block completely on the pass. side and do have that opening for the tranny cooler though. do you have a cooler?

[darcane]

Yeah, I have a tranny cooler, that's the reason for the gap on the driver's side of the grill block.

I notice the temps creeping up, but it's still not getting "Hot" and the clutch on the fan isn't engaging (mechanical fan is really noisy when the clutch is engaged and I can definately hear it in the cab).

It's just that it's something I'm keeping a close eye on now and noticed a change in behavior.

[ECONORAM]

Originally Posted by aerohead

I went back over the Crisis Fighter Pinto article from back in 1974.Here are some data Car and Driver got from their mods:
*low airdam ( 2-inch ground clearance)= 10% delta Cd / 6.16% + mpg @ 70 mph
* complete grille block with airdam = 22.831% delta Cd/13.69% + mpg
*compromise grille block with airdam = 15.98% delta Cd/9.59% + mpg
* grille block alone = 4.56% delta Cd/ 2.739% + mpg
* 2-blade cooling fan vs 4-blade = 0.5 mpg= 5.7% delta Cd/3.4% + mpg
* complete fan removal= 1.0 mpg= 14% delta Cd/ 6.84% + mpg

Hmmm. I have noticed my temps creeping up with about a 1/2 grill block, as it gets over 100 in northern TX. Highway only a couple degrees, but in the city it is up quite a bit. I wonder if I revert to my old clutch fan (instead of the e-fan) if I can increase the grill blockage past 1/2 and not affect temps...

[Frank Lee]

You are proposing reverting back to a less efficient fan system AND covering up the grille MORE so that said fan (or any fan for that matter) runs more vs simply letting the air pass through?!?

Me thinks you need to have another beer.