I added a $300 chip and get 20mpg on the road and 16mpg around town. it's amazing for a truck that large to have as much power, confort and gas economy. I will put it up next to a Ford or Dodge any day.
At 10k miles my truck started
knocking. Now at 25k it knocks all the
time. Complained to dealer and GM,
they extended engine warranty to 5
years/100k miles. What good is a truck
that cost $30k that I have to get rid
of in 5 years if it doesn't blow
before hand? This is from a 40 year GM
loyalist and shareholder.
Search "piston slap" on the internet
for all the sorry details.