Gas pump with one hose?

Hello, if buying mid grade gas and the pump only one hose for all the grades how much of the last grade to you get? All the stations around here only uses one hose, so if I want mid grade and the person before me got reg do I end up getting what is in the hose before I get what I wanted? I buy only one gal at once most of the time so do I get part in the reg grade. Or does the hose gets pumped back when it is shut off. If don't I feel like i'm getting what I pay for. Has this ever been checked?
Thanks!

I've always wondered about this too but I have never seen anything stating whether or how much fuel is left in the hose.

. (this dot is a molehill)

O (this circle is a mountain)

Just make sure you're following someone who fills up with premium and you're a winner!

Right, that hose can hold quite a bit of gas and it is the gas that was pumped last. Usually doesn't matter but when getting only a gallon...

I always pump a couple gallons into my truck first then fill the gas can. That way I know I'm getting the 89 octane.

I always check the price/litre (price/gallon for the rest of us) on the pump against the price for reg. mid grade & premium. If the last guy pumped premium, then I'll use that pump.

Simple solution: pump a gallon or two of that premium into your truck, before filling your chainsaw tank. Putting a few gallons of premium in your truck may go against your principles, but it's a cheap way to ensure you're running hi-test in your saws. Your truck needs gas anyway, and the price difference between 93 and 89 octain won't kill you on two gallons.

Go to a marina & buy 91 octane ethanol free, or the local airport for 100 octane LL AV gas, problem solved. A C

+1

Had this problem quite a bit with motorcycles that required premium gas to run correctly. Most of the time the bike would only take 3 gallons or less unless I had run it dry. I like the suggestion to pump at least a gallon into your car/truck tank, then fill your can. One or two gallons of premium in your 30+ gallon truck tank ain't gonna amount to ....

This is the way to go!
AV gas smells great too. Use Klotz as the premix and it'll smell good as beef stew cooking on the woodstove! You'll think you're at a spa.
When racing 2 strokes back in the late 80s I found AV gas left the top end cleaner on my CR500 too.

What's wrong with corn gas?

Ahh... the smell of race gas on a cold race-day morning. Wish I could bottle that.

I remember when motorcyclists used to go to gas stations after hours and fill their tanks with what was left in the hoses.

Am I the only one that runs the cheapest gas sold in my saw? It's a chainsaw, not a race car!

Chainsaws are high compression engines, just like race cars. I'm not sure how the price of your saw stacks up to a few pennies saved per gallon, but it's likley best to run some decent octain and avoid pre-ignition.

I should tell that to the old saw I had I guess. Had run hundreds of cords through it on the factory motor before I sold it.

Same here. Word I got was it's more an issue with modern saws than older saws. I had never run anything higher than 87 octain thru any of my 1970's / 1980's saws, before I came here. Now I have new saws, and am forced to buy this fangled 93 octain stuff.

And don't you dare forget to add your Stabil...

The saw manual will tell you what octane of fuel it was designed for. Using lower or higher octane can cause damage. I follow directions written by the men that engineered my equipment and use regular gas.

Haven't used it in years, and never had a problem. Maybe ignorance is bliss?

You are not alone, I run a12yearold 372 xp and 6 year 350 on 87 octane.
I buy my gas at a very busy sation, no stabil added, 30 days out it go's in truck.
Both saw drop start at three pull's cold. Maybe four.

Is it ok to run 50:1 in a modern 4 stroke engine?

I've always been told high octane gasoline burns slower & runs cooler in all 2 cycle engines. The main reason high octane is good in 2 cycle engines is for the cooler operating temps , not more power.
Which to me translates: faster burning, regular gasoline gives 2 cycles more power but higher exhaust gas temperatures & more of a chance to burn/scorch the piston.
&
the higher the octane rating, the slower & cooler burning with less power.
So if the saw manual says 87 octane (like in my manual) & you burn 91 octane, you get less power out of more expensive gasoline. (but lower exhaust temps)

Lower octane than the saw is rated to operate on is more damaging than higher octane due to the increased exhaust temperatures.
But the potential for me to be wrong is huge.

Octane is added to gasoline to increases the ignition compression pressure of the fuel gas mixture so it doesn't pre-ignite before it is ignited by the spark plug (ie: knocking in during the compression stroke.) A problem for high compression, high performance engines running on regular gasoline. Which can occur on 2 cycle engines also & cause engine damage.

Not sure, but i'd think it may cause the catalytic converter to get hotter than normal since it has to burn the oil that will be in the exhaust.