What are the differences in a 4 vs 6 speed automatic transmission in a GMC 2013 sierra truck? Why would one be better over the other? Comments?
It all depends: A 4 speed is less complicated, has fewer parts and clutches and has the potential of having heavier gears. The downside: It has only 4 gears; the spacing of the gear ratios may not be optium. The 4 speed probably is an older design and well developed. Four speeds have been used for years and were ok.
The 6 speed offers better matching of engine output to vehicle speed, but has more parts. if the transmission case is about the same size as the 3 speed, this means that extra gears are stuffed into the same space as the 4-speed. The 6-speed may get better fuel mileage depending on many factors.
Best choice depends on the engine and you did not say which engine you have. If you have a 'honking' big V-8 with a flat torque curve, a 4 speed should be ok.
If you have a small v-6 or 4 cylinder, the the 6 speed is definitely better.
The engine for the 6 speed is a 5.3 liter V-8....how does that sound?
you forgot to consider usage such as hauling a payload, or trailer and what the final drive ratio is. I don't know any of the specifics of th GM Sierra, but as jem said, two more gears can be helpful for starting out while pulling or towing and also for gas mileage at cruising speeds.
Can u get 2 identical optioned trucks with either trans? Or does 6 speed require a premium package?