I had a unique opportunity to try out a hood scoop this week.

I live in San Jose CA and drove up to Reno NV. While there I visited Rob and Lorrie of Humhers, http://www.humhers.com. Rob set me up with a hood scoop and bug deflector. I also got some other goodies as well, more to come. Wow, someday I want a shop just like Rob and Lorrie's. They are set up to fabricate just about anything imaginable. Check out their company web site at http://www.rscher.com. They make some pretty cool stuff.

The hood scoop is clear poly carbonate that does somewhat distort things but does not impair over the hood visibility. The front opening of the hood scoop is nominally 24" by 5 1/2", it is big. The top of the hood scoop extends to the front edge of the hood.

Installation was pretty straightforward, remove the six bolts that secure the hood louver. Slip the front bracket under the hood louver. Bolt the back of the hood scoop to the hood and install the front grill bolts. Attach the front corners of the hood scoop to the bracket and installation is complete. The bug deflector is attached to the rear three bolts of the hood scoop.

Observations: It is a 4 1/2 hour drive from San Jose to Reno. For those of you not familiar with the area you start at sea level, drive across the central valley, climb to over 6,000' and descend into the Reno valley. I have temp gauges on my transmission and transfer case. My truck is a 95 normally aspirated diesel wagon with MT tires and the AC was on. I drove out during the warmest part of the day. In the central valley it was about 85F cooling down to the fifties near the summit on Hwy. 80. Driving 68 MPH the engine temp was 205, trans. 190, transfer 220. The engine fan was running intermittently until I started the ascent into the mountains then the fan ran almost continuously. My speed dropped as low as 45 and the engine temp would occasionally get up to 210. The transmission temp increased with the shifting activity. Interestingly as the speed dropped the transfer case temp dropped.

With the hood scoop installed, the max. engine temp was 200 while climbing to Donner pass. With the central valley temp in the low 90's the engine ran at 195 and the transmission ran at 180. The transfer case still eventually got up to 220. One very noticeable difference was that the engine cooling fan only came on twice during the trip home. Both times were within 1 mile of the summit at Donner pass. Apparently at freeway speeds the scoop forces sufficient airflow through the stack without the fan. Keep in mind the Hummer has a really big fan. I don't recall how much horsepower it takes to spin the fan, but I would rather use the power to move the Hummer. The air conditioner also felt colder. Unfortunately I didn't have a temp gauge to quantify the difference. Another interesting observation was when the window was lowered at freeway speeds there used to be a blast of hot air that would come up from the shifter and parking brake boots. Although the air was still warm, it was not hot. I think the scoop is forcing a lot more air down into the tunnel area.

The bug deflector did what Rob promised. Although the more massive bugs still hit the lower part of the window, the smaller insects plastered the upper 1/3 of the window or missed altogether and hit the roof rack (there are a lot of bugs in the central valley).

If you spend a lot of time at highway speeds you probably should consider installing a hood scoop. If you live in an area with a lot of insects give the bug deflector a try.

-william