I store my Miata for the winter; usually 3-4 months. I fill the tank with 93 octane and add some Sta-Bil. I'm curious to know if, during storage, the octane rating changes. I've never had a problem starting the car when good weather arrives as it starts quicker than my DD.
Will the octane change?
- Thread starter Mar57
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I wouldn't worry too much in a modern fuel tank in good condition - even with ethanol. The system is pressurized with fuel vapor, so oxidation isn't so much of an issue. Water vapor isn't a problem either since the air should be purged. The biggest issue will be in a gas can, even with the newer ones that are designed to minimize leaking vapor. Exposure to oxygen and water can eventually lower the octane rating.
I had a car that wouldn't work properly for more than 9 months before I had it fixed. The engine operated normally even with the same fuel sitting there.
I had a car that wouldn't work properly for more than 9 months before I had it fixed. The engine operated normally even with the same fuel sitting there.
Todays premium is the 1970's regular.
I would imagine that a Miata doesn't require a fuel with an octane rating as high as 93, so I wouldn't worry too much.
Actually the OM calls for premium gas. There are some Miata owners that run their cars on regular but performance and gas mileage go down. Until recently I have been running it on 89 octane. Performance and mileage on 89 are good. Recently a new Costco opened up near me and I've been getting gas there .. best prices in town. This location only offers two flavors .. regular and premium (93 octane). The car runs very well on 93 and the really good thing is that the price is lower than I've been paying for 89 octane.
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u should be ok
The industry standard is for gas to remain fresh for 6 months. Just keep the tank full (90%+) to avoid any condensation. The Stabil is not necessary but its great insurance. The octane is a total non issue.
Originally Posted by JohnnyJohnson
Todays premium is the 1970's regular.
Run 1970's premium for 20000 miles in a modern car and report back.
Todays premium is the 1970's regular.
Run 1970's premium for 20000 miles in a modern car and report back.
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Originally Posted by Mar57
Actually the OM calls for premium gas. There are some Miata owners that run their cars on regular but performance and gas mileage go down. Until recently I have been running it on 89 octane. Performance and mileage on 89 are good. Recently a new Costco opened up near me and I've been getting gas there .. best prices in town. This location only offers two flavors .. regular and premium (93 octane). The car runs very well on 93 and the really good thing is that the price is lower than I've been paying for 89 octane.
I use my credit card twice when mid-grade is not available.
Vehicle owners should already know their tank volume size and determine the amount of gallons needed by the gas gauge reading. So if I determine I'll need approx 16 gals of fuel, I will buy 8gals of premium - then after receiving my paper receipt, I will buy 8 gals of regular, without moving my vehicle.
Actually the OM calls for premium gas. There are some Miata owners that run their cars on regular but performance and gas mileage go down. Until recently I have been running it on 89 octane. Performance and mileage on 89 are good. Recently a new Costco opened up near me and I've been getting gas there .. best prices in town. This location only offers two flavors .. regular and premium (93 octane). The car runs very well on 93 and the really good thing is that the price is lower than I've been paying for 89 octane.
I use my credit card twice when mid-grade is not available.
Vehicle owners should already know their tank volume size and determine the amount of gallons needed by the gas gauge reading. So if I determine I'll need approx 16 gals of fuel, I will buy 8gals of premium - then after receiving my paper receipt, I will buy 8 gals of regular, without moving my vehicle.
Originally Posted by JohnnyJohnson
Todays premium is the 1970's regular.
Not at all. The standards for fuel today are much higher. 70s regular would have been 86 AKI octane, and that's with lead.
The only issue would be certain older engines that would need the lead to protect valves.
Todays premium is the 1970's regular.
Not at all. The standards for fuel today are much higher. 70s regular would have been 86 AKI octane, and that's with lead.
The only issue would be certain older engines that would need the lead to protect valves.
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