My first full sized truck. 5.3L engine has been great. The truck has 80k miles and has had very few mechanical problems. I easily average 16 to 18 mpg around town and 20 to 21 mpg on hwy which is darn good for a full sized truck.
Comfort and power plus fuel economy for a large vehicle. Excellent overall reliability so far (7 years and 80k miles). Great engine/transmission access and design. Good brake design. Good tow vehicle.
Wind noise from rear side windows. Paint clear coat (I've noticed minor defects as it ages). The single mechanical problem has been the drivers-side power window motor/cable assembly. I've changed it twice. Unacceptable! Drive shaft slightly imbalanced at low speed towing uphill.
99 Sierra SLT Ex. cab. Just hit 127k.
Extremely reliable. No issues. Slight
engine tapping for 30 seconds when
cold. Does not burn oil. Have
mainitained very well. Orig. trans
mission that shows very little wear
when the filter is replaced. Very
quite, comfortable, fun to drive while
still delivering decent mileage 15/19.
This is my 2nd GMC truck. My 1991 was
sold for 50% of what I paid for it with
160000 miles. It was also very
reliable. My father drove my 99 Sierra
a couple of times and sold his 1990
FORD truck and purchased a new 2000 GMC
Sierra Z71. He loves it. (so does mom).
The transmission tow/haul feature works
great with heavy loads. The driver
information center is very informative.
The power is the best. I love gunning
it at about 30 mph having my spine
realigned. Quiet and smooth ride.
The amount of space in the extended cab
is more than ample.
The headlight system is automatic on
this model and does not have a manual
override. Slight tapping when starting
engine for about 30 seconds. I have
heard of other models doing this.
Supposedly it is a charactoristic.