backstory is that i try to fill up my tank more when gas prices are at a low and less as prices go up to make my long term average cost per gallon lower.
now given current events, and empirical reality, gas has only been going up and will continue to go up. we could assume different curves(only constraint being that price per gallon goes up as time goes forward), but if you buy your gas now you will spend less money then you have if you bought it tomorrow, day after, or week down the road. my estimate is that it will be month minimum before it gets cheaper.
now that I have put this out there into the world you should fill up asap, I already filled up before making this post and other people will come up with this idea independently of me.
What happens with old fuel after 3-6 months? People with oil heaters often keep their diesel around for >1 year …
Diesel has roughly ~double the shelf life as “normal” gas, so 6-12mo instead of 3-6. It doesn’t just immediately go bad, but loses its energy slowly and burns less cleanly, so it could cause engine issues, but that’s not super likely unless you’ve been storing it for a looong time.
I own a regular gasoline truck. It once spent over a year sitting in a driveway with no battery or driveshaft, and a half filled tank of gas.
After putting in a new battery and drive shaft, I didn’t remember how much gas was in it anymore, so I took my 2gal can and put abiut half in to get it started.
No issues starting beyond the usual no gas primed in the line or fuel rail, so it took a second, and I drove it for about 50 miles before stopping at a gas station.
I have also never once swapped the gas in my mower after letting it sit all winter.
I understand that gas degrades, I just have never had gas that sat long enough to go bad I guess? I don’t think 1 gallon of gas would “fix” 15 gallons of bad gas…
Lawn mower engines operate on nearly anything though.
Same with old vehicles, although newer gas with ethanol eats up the rubber.