2020 GMC AT4 MPG Disapointed

[JD19]

1 minute ago, Ryno12 said:

Small motors don’t necessarily equate to good gas mileage. That little engine has to work a lot harder to get that truck moving than the larger V8’s. I would think certainly a 5.3, & quite possibly even the 6.2, would get better gas mileage than your 4.3.

You're correct.  I did have the 5.3 and 6 speed in my old 2010 Sierra.  It got the same mileage as the 4.3 in my new 19.   I did notice that 4.3 isn't programmed to stay in V4 mode as much as the 5.3 is/was.  Nonetheless, the shape of the truck is still, in my opinion, the main factor.   The 4.3 V6 in the 14-18 models seems to have achieved better mpg than the same set up in my 19.  The engine itself is actually quite good in terms of performance and is similar to the 5.3 in my old 2010.  I would have loved to have gotten the 5.3 again but the only ones the dealer had access to would have ended up costing a significant amount more since it came in a package with other items.