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invmartyc's avatar
invmartyc
Explorer
Apr 09, 2014

What grade of gas does your large gas engine require

With the big V-8 and V-10 engines do you have to burn a higher octane than regular unleaded? Back in the days of muscle cars you had to burn premium.

Does that apply to big blocks in RVs?
Class A

18 Replies

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  • BobR's avatar
    BobR
    Explorer
    Apr 09, 2014
    Old Ford 460 running 87 octane per owner's manual.
  • K_Charles's avatar
    K_Charles
    Explorer
    Apr 09, 2014
    The compression ratio is only about 9:1 so you can use regular gas. They have found better ways to make power then raising the compression ratio.
  • dayakster's avatar
    dayakster
    Explorer
    Apr 09, 2014
    The previous owner of my 97 Allegro Bus said he ran regular too. Thanks for the question as I was in need of opinions also.
  • Coyote74's avatar
    Coyote74
    Explorer
    Apr 09, 2014
    My 8.1 GM workhorse uses regular gas. I had a 454 chev used reg and 2 workhorse over the years all ran fine on reg gas. East coast, south and north plus Midwest areas.
  • fourmat's avatar
    fourmat
    Explorer
    Apr 09, 2014
    the premium requirement in old big blocks was due to compression ratio and carb the V10 has EFI fuel management and runs on regular

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