Please bear with me, because this is my first post. I have a 1999 Chevrolet tracker with the 2 L engine it's pretty much stuck with the exception of the cold air intake. I use it a lot to go camping around the state, which is perfect for. I've noticed while driving on The interstate  that my gas mileage really isn't any better than driving in town. I also noticed that my RPMs are pretty high between 70 and 80 mph. Does anybody know of a six speed manual transmission that Has ever been installed on a tracker or GV? I have also noticed that there are very few aftermarket modifications for this vehicle, and why just not looking hard enough?

well at 70 mph I run at 3000 rpm but I run 512s and 30" tires  in my 2002 2dr 5 spd. there really isn't much for after market part but they are slowly coming out

Hey Phuzz,
A six speed may not be the answer.  In many cases, a six speed tranny just has closer gear ratios between the gears.  The sixth gear is often the same ratio as fifth on a five speed.  I have never seen a six speed sway that didnt also include an engine from another manufacturer.

how about an aftermarket add on overdrive?

It is spinning at a high RPM at 70-80mph because the power generated at that rpm is what is required at that velocity and a decent size load.

Remember, this is a small 4-cylinder engine pushing a 2,800 lb vehicle.  It is not a V6 or a V8 with a lot of extra power capacity.