2021 Tahoe-High Country

[dei3333]

Just bought a 2021 Tahoe High Country- In reading the manual, it recommends I use 91 octane or higher. Is this necessary ? What happens if i only use regular gasoline ?

Dei3333

 

[Doubeleive]

nothing, it just runs better on higher octane, you have to be in "tune" with your vehicle to notice any difference
it's possible if you ran some pretty terrible fuel you may hear or notice "engine knock" while accelerating up a hill or something, the ecm is designed to try and prevent that kind of thing even if running lower octane.

 

[Z15]

GM engines that recommend premium grade gasoline are more efficient, get better fuel economy which increases the power and efficiency of those engines. They might not tolerate lower octane and if you hear detonation (pinging) engine damage is occurring.

I read some time ago about GM advocating that 91 should be the new norm in the US because they can design engines to be more efficient on that.

I found a link to that story... https://gmauthority.com/blog/2017/04/general-motors-calls-for-standardized-high-octane-gasoline/