I have a 2005 H2 with the LQ4. I started a tune up with new plugs and wires. My gas mileage is 11mpg, and I do not seem to have as much power as I once had. Any suggestions? Is there a better than stock coil pack? I don't want to spend twice as much for "name brand" if they are no better than stock AC Delco.
Thanks

 

I have not gone aftermarket so I don't have first hand experience. I know some have but 11 mpg is pretty normal for these things. You can throw in aftermarket coils, plugs, and wires and see but AC Delco is the safest bet. I have read some stories of issues with aftermarket parts in that aspect.