Stupid question: I know this is kind of a dumb question but what purpose do unleaded plus and unleaded premium serve?
Like regular unleaded exists.
I know diesel I guess is for trucks and trailer tractors but what are the other two unleaded for? Does it make your car go 45 mph if you're going 30 mph?

>>937391637 (OP)
Engines with higher compression ratios (sports cars, luxury, etc) need higher octane levels to operate. That's in the least amount of words.

>>937391776
So diesel is for trucks, regular unleaded is for your commuter sedans, suvs, and the rest are for other types of vehicles that have different requirements.
Do those unleaded fuels have reverse compatibility? Like if you accidently use premium or plus (different octane level) on a regular car, is it like trying to use a ps3 disc on a ps1 or is it not an issue?

>>937392024
Premium gas in a regular car just gets burnt up with no benefit, and you maybe risk engine damage. On the flipside, low octane gas in a premium engine will really fuck with it. Now, of course, there are outlier models that can tolerate multiple grades. Additionally there's the whole other can of worms that is "flex-fuel".