Our 1995 Chevy Suburban K1500 4WD with a 350 received the Gadgetman Groove in April of 2010. Before the Groove the truck was getting 12 to 12.5 miles per gallon...two weeks ago, after a restriction in the intake air pathway, it reached 17.6 miles per gallon. A 40.8% gain in efficiency!!

This is very exciting because over the past year I have done the following to this vehicle since the Groove modification:
1. Plugged PCV, EGR and Evaporative Emissions exits from TB
2. Moved MAP intake further away from throttle body...since returned to original
3. Replaced leaky brake booster
4. Replaced IAC Valve
5. Repaired leaking plug in the intake.
6. Replaced intake gasket
7. Changed and increased gaps on spark plugs
8. Repaired/Replaced entire exhaust system to make it leak free
9. Installed then uninstalled an EFIE

During this year long process the truck did show gains in the 14 mpg or less range (most times closer to 12), so there was some gain. The 'burb seemed more smooth and powerful but I wasn't content with the efficiency gains.

Recently I dramatically reduced the intake air pathway and re-routed it farther away from the area of the Groove and that made the difference...17.6 mpg!

When you increase the throttle you can hear the Groove working as the majority of the air goes over the Groove now. Quite a sound

This goes to show, in the extreme, that the Gadgetman Groove is a process. Sometimes results are experienced immediately, but many times you need to work on the process before results are truly realized.

Very soon I will post a service bulletin to share with you all how to reduce the intake air pathway on all TBI units from 1987 to 1995.

Please post any questions or comments you may have concerning the Suburban adventure.

Great post, Nick!

As you say, this is an extreme case, but now the entire Gadgetman World is better for the experience.

Thanks for sharing!!!

Ron

The last tank (42 gallons)showed 15 miles per gallon. To clarify, pre-groove the truck was getting 11 city and 13 highway. This tank was city (as city as we get here). So the official results on this modification is from 11 to 15 city and 13 to 17.5 highway, a solid 35% gain. Amazing what a little groove can do.

I am selling the truck on Craigslist. Here's the link: rochester.craigslist.org/cto/2433850735.html.

There is a new service bulletin located at: www.gadgetmangroove.com/index.php?
option=com_phocadownload&view=category&id=2:certified-gadgetman-
documents&Itemid=429

This document outlines the process to reroute the idle air pathway for 1987 to 1995 trucks with 350 and 305 TBI units. It is the process used to finally get the gains on my Suburban. Check it out.

The suburban was sold yesterday. On to the next project!