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Anyone know why V8 engine oil capacity went up significantly from the 1990's era to 2010 and onwards (not sure about exact dates), but I can recall a chevy 350 for the longest time requiring only 5 qts for a full change, but now its 8qt for at least 2021 and newer. Just curious what the argument was behind that.

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  • BTW ... Welcome to Motor Vehicle Maintenance & Repair! :o) Jan 13, 2023 at 12:44

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There are two main reasons for this. One being so vehicles can go longer between oil changes. Another being with different things within the engine being controlled by oil pressure, such as variable valve timing (VVT), more oil is needed to ensure a constant supply. Without the constant pressure supply, these things would run erratically.

GM wasn't the only manufacturer to put extra oil in engines. If you look at some others:

  • 2016 MB S550 4.7L V8 - 8.5 quarts
  • 2020 Dodge Challenger 6.2L V8 - 7 quarts
  • 2020 Porsche 911 3.6L H6 - 8.5 quarts

And the list goes on. Also remember, it's not just the GM trucks which have the larger capacity. Any of the GM vehicles which run the LTx engines (Camaro, Corvette, Suburban, Express vans, etc), have the higher oil capacity. The smaller GM engines aren't running as much oil, but they are running more oil than you'd think. Even the GM 3.6L V6 used in most of the small to mid-sized SUVs run 6 quarts.

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  • Thank you! That is the best answer ive seen anywhere on this.
    – bitshift
    Jan 13, 2023 at 11:48
  • I believe another reason is that as engines have been "leaned" out more and more for emissions compliance, more heat is generated and that is harder on the oil. Having more oil provides more time for the oil to cool before being circulated back into the engine.
    – jwh20
    Jan 13, 2023 at 20:16
  • @jwh20 - They really haven't been leaned out. There are two huge things with leaning it out. First is, the larger chance of detonation/knock. Second being, as you lean it out, the combustion process gets hotter (as you suggested), which creates more NOx. Manufacturers have to deal with emissions and creating more NOx is not a good way to go about it. I can see your point about more heat in general though, and yes, more oil works better for keeping things cooler. Jan 13, 2023 at 21:46

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