Does gasoline lose octane over time? (Tune related)
#1
Does gasoline lose octane over time? (Tune related)
My car is a nice-weather weekend car that does not see all that many miles, especially over the Winter months. Over the Winter I can go for as long as 6 months between fill ups, but I do add stabilizer when I fill up for the last time before it sits for a while.
My concern is, when I load a higher octane tune (93), will I run into issues if I'm not filling up at least once a month or so? Currently I have a nearly empty tank with 87 in it (with a Bama 87S tune), but I plan on running through a tank of 93 before loading a 93 tune. I then don't want to run into problems if the octane rating lowers over time while I have a 93 tune loaded... or is this not something to worry about? I suppose I could continue filling up with 93 and then run a 91 tune to be safe, but I'd prefer to run a 93 tune with 93 gas if possible.
Any thoughts?
My concern is, when I load a higher octane tune (93), will I run into issues if I'm not filling up at least once a month or so? Currently I have a nearly empty tank with 87 in it (with a Bama 87S tune), but I plan on running through a tank of 93 before loading a 93 tune. I then don't want to run into problems if the octane rating lowers over time while I have a 93 tune loaded... or is this not something to worry about? I suppose I could continue filling up with 93 and then run a 91 tune to be safe, but I'd prefer to run a 93 tune with 93 gas if possible.
Any thoughts?
#2
you need to add stabilizer before the fuel sits...adding it afterword wont help old fuel. The main problem with letting fuel sit is some of the components of the fresh fuel evaporate, lowering the volatility and the fuel can become contaminated with water from the air. I cant comment on what could happen with a car engine if you run it. I read that higher octane fuel can degrade in only 60 days...there is also no good way to know how old the fuel was when you first bought it...if its not too much, maybe you can siphon it out and use it for the lawnmower.
Last edited by vixr; 05-19-2013 at 04:38 PM.
#3
6th Gear Member
My Stang will often sit for a few months with the same fuel and I haven't noticed a problem with my 89 tune. When I used to store the Stang over the winter (when I lived in that god-forsaken north) I used stabilizer. But now I use ethanol free fuel plus I'll occasionally use stabilizer when I know it'll be awhile before she gets her tank emptied.
#4
you need to add stabilizer before the fuel sits...adding it afterword wont help old fuel. The main problem with letting fuel sit is some of the components of the fresh fuel evaporate, lowering the volatility and the fuel can become contaminated with water from the air. I cant comment on what could happen with a car engine if you run it. I read that higher octane fuel can degrade in only 60 days...there is also no good way to know how old the fuel was when you first bought it...if its not too much, maybe you can siphon it out and use it for the lawnmower.
#5
6th Gear Member
Incorrect method. You're not getting the proper mixing required to provide protection, nor is any of the properly treated fuel getting thru your fuel system. Add the stabilizer at the pump BEFORE filling to allow the stabilizer to mix from the force of the fuel entering the tank. Then, as you drive home (as long as it's more than just a couple of miles), the treated fuel is now in the lines, injectors, etc at time of storage.
#6
Incorrect method. You're not getting the proper mixing required to provide protection, nor is any of the properly treated fuel getting thru your fuel system. Add the stabilizer at the pump BEFORE filling to allow the stabilizer to mix from the force of the fuel entering the tank. Then, as you drive home (as long as it's more than just a couple of miles), the treated fuel is now in the lines, injectors, etc at time of storage.
#7
Incorrect method. You're not getting the proper mixing required to provide protection, nor is any of the properly treated fuel getting thru your fuel system. Add the stabilizer at the pump BEFORE filling to allow the stabilizer to mix from the force of the fuel entering the tank. Then, as you drive home (as long as it's more than just a couple of miles), the treated fuel is now in the lines, injectors, etc at time of storage.
#8
Gasoline does not lose octane over time. It degrades.
That said, every single tier one gasoline supplier in the United States has a minimum one year storage life for gasoline.
Adding Stabil for winter storage is a complete waste of money unless your winters are 13 months long. Using one tank of gasoline per month doesn't require anything but filling up once a month.
The Chevy Volt has a battery pack that's charged overnight and a gasoline engine that acts as a generator if you drive further than the small battery's range (about 40 miles). If you drive less than 40 miles a day and recharge every night, the gasoline engine will never turn on. Drive over 40 miles, the engine kicks in and generates electricity for the electric motor powering the drive wheels.
Chevrolet has programmed the Volt's computer to deal with the possibilty of stale gas. If you drive only on the electric charge, the gas engine will never turn on and you eventually wind up with nine gallons of goo.
Several Volt owners have reported driving over a year without using any gasoline and the Volt's computer turns on the gas engine around thirteen months (there are variables) after the last fill up to burn the gasoline before it goes stale.
No additives required with brand name fuels. Yes, I've personally spoken with specialists at Conoco-Phillips and Chevron and have a Conoco-Phillips White Paper to verfy this
That said, every single tier one gasoline supplier in the United States has a minimum one year storage life for gasoline.
Adding Stabil for winter storage is a complete waste of money unless your winters are 13 months long. Using one tank of gasoline per month doesn't require anything but filling up once a month.
The Chevy Volt has a battery pack that's charged overnight and a gasoline engine that acts as a generator if you drive further than the small battery's range (about 40 miles). If you drive less than 40 miles a day and recharge every night, the gasoline engine will never turn on. Drive over 40 miles, the engine kicks in and generates electricity for the electric motor powering the drive wheels.
Chevrolet has programmed the Volt's computer to deal with the possibilty of stale gas. If you drive only on the electric charge, the gas engine will never turn on and you eventually wind up with nine gallons of goo.
Several Volt owners have reported driving over a year without using any gasoline and the Volt's computer turns on the gas engine around thirteen months (there are variables) after the last fill up to burn the gasoline before it goes stale.
No additives required with brand name fuels. Yes, I've personally spoken with specialists at Conoco-Phillips and Chevron and have a Conoco-Phillips White Paper to verfy this
Last edited by Sonic Mustang; 05-22-2013 at 08:37 PM.
#9
Once I realized I can drive a Powerstroke 4X4 in winter mostly in 2wD with 570lb.ft. torque and an empty bed without hitting anything, the Mustang was a piece of cake on all season tires. Just be gentle with the throttle and don't drive faster than conditions allow. Most people drive way too fast in winter regardless of tires.
#10
Good question I was actually thinking the same thing since after this weekend hopefully I will be getting a daily driver and mine will no longer be driven daily. I wonder this because my car is supercharged and is tuned for 93 octane.