More 5.3L Engine Research

Discussion in 'Performance & Fuel' started by Goldie, Feb 8, 2012.

  1. Goldie

    Goldie Epic Member 5+ Years 1000 Posts

    I'm still continuing the research and pricing for a Sierra 1/2 ton W/T and I'm leaning towards the 5.3L engine. I'd like members opnions on this engine since it is an $1,770 option. Also, how do folks like the AFM feature of the engine? Finally, how can you tell when you are in the AFM mode? Is there some kind of indicator/signal or what?
  2. coreyallen11

    coreyallen11 Rockstar

    So far with our 09 silverado its alright its right in the driver information center when you have the instant fuel eco on. I think some one else will chime in Im sure and correct me
  3. KWG08VMI

    KWG08VMI Rockstar 100 Posts


    I would definitely say that the 5.3L is worth the money. Especially if it has the AFM. I have a 2010 1500 with the AFM on it and I love it. I average 19.5 mpg during the week and about 18 on the weekends running around town. Coreyallen is correct, if your Driver Information Center (DIC) displays all of the information it will tell you if the motor is in 4 or 8 cylinder mode. I didn't get all of the options on my truck so my DIC doesn't tell me when it's in 4 cyl. mode.
  4. Goldie

    Goldie Epic Member 5+ Years 1000 Posts

    Thank you for the information. It helps in making a decesion. And ,yes, I'm strongly cosidering the 5.3L.
  5. 747

    747 Member 2 Years 100 Posts

    The 5.3 is totally worth the money, especially if you get the 6 speed transmission with it. We have two Silverados with AFM and it works seamlessly on both of them.
  6. AMac

    AMac Rockstar 3 Years GMTC Chick 500 Posts ROTM Winner

    I had an '09 Sierra with a 5.3 and the AFM and was getting about 18-19 MPGs. In my new beast, '11 Silverado 5.3 w/ AFM I can barely get 15. I'm anxious to find out if it's because of the cap; I still have oem wheels so why such a difference, I don't know.

    What was the other engine option you were considering?
  7. Goldie

    Goldie Epic Member 5+ Years 1000 Posts

    AMac - I was looking at the 4.8L. But when I thought abaout the mods I would add, I'd end up (probably) with a 4.8L that performed like a 5.3L. And if I end up with the 5.3L I'm planning on addding mods.
  8. Untouchable

    Untouchable Member 2 Years 100 Posts

    I would have to agree with everyone else that the 5.3 is worth the money.
  9. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    If your still searching for a Silverado with a 5.3/6 spd look for one with the "All Star" package, the package runs a little under $2000 but includes the 5.3/6 spd combo and a few other nice to have extras like Blue Tooth, Power Drivers seat, trailering pkg, and additional extras I'm forgetting.
    The 5.3 definately has a few extra ponies over the 4.8 and with the 6spd auto the MPG is slightly better than the 4.8.
    5.3 equipped trucks with 20" wheels seem to be averaging a few MPG less than those with the 18" wheels.
    There have been some complaints of thunking from the transmission during downshifts from 6-5 and 2-1, but overall the transmission shifts smooth.
    One issue with the 5.3 and AFM I dont particularly care for is the fact that GM has made it extremely hard to modify anything on the drivetrain unless you get the computer tuned after the change. Changing an item as simple as the muffler can lead to erratic shift patterns of the transmission and stop the AFM from cycling to the 4 cyl mode.
    Some tuners have made it possible to turn off the AFM and those that have went this route report no loss of MPG.
    Overall its a great choice for an engine trans package.
  10. bachus

    bachus New Member

    I have a 2007 GMC Sierra extenda cab half ton 4 wheel drive SLT. I like the truck, has a few squeeks but am taking care of one by one. I have the 5.3 AFM find the MPG is decent but do not like the oil consumption that started around 58000 mile It now ha app 68000 mile on it and uses two quarts every 3000 mile which is when the oil gets changed. From doing research they blame it on the AFM. Very disapointed with that but only have a couple payments left so I guess I am stuck with it. I have Ford in the past put over 125000 miles on and never added oil. Hope this is something that GM can solve. I really didn't want to start the paymeny club again. Gonna retire in two years.

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