Will 93 octane hurt anything?

[IDFISHER]

I was on a camping trip and a buddy gave me his gas can to top off my fuel tank and I didn't learn until later that it was 93 octane. I had about 3 gallons of my usual 87 octane non E in my 6 gallon tank and put about 3 gallons of his 93 to top it off. I haven't run it yet but just wondering if that will cause any issues. If so, i'll burn it in something else and put fresh fuel in my boat. Motor is a '94 60 HP 3 cyl. Thanks.

 

[GA_Boater]

Of course not. Just use it.

 

[boobie]

Run it, use it up.

 

[ThomW]

Might burn cleaner, less or no ethanol. Nothing to worry about. Just better gas.

 

[jimmbo]

Higher Octane fuels may leave more deposits on the spark plug. It actually burns slower than Lower Octane fuels, which is why there is absolutely no reason to use a higher Octane than is required

 

[maybe368]

jimmbo is correct, octane in fuel is an inhibitor that is intended to prevent preignition of the fuel, otherwise known as pinging. This was meant for high compression, high performance engines because pinging could destroy such engines...Mark

 

[Bosunsmate]

91 and 95 are the only petrol fuels supplied here and ive being running mine for years on that, no problems. Thats like hundreds of gallons compared to your 3

 

[jimmbo]

The Octane Rating Scheme is often different in Countries outside of North America. Our 87 might be the same as your 91.

 

[maybe368]

I remember when premium was 100 octane and regular was 90. In the 1970's, during the gas crisis, compression ratios went from 9:1 to 11:1 for the muscle cars, to 6:1 to 8:1 for all cars. Nowadays, performance is much more driven by turbos than compression ratios...Mark

 

[Scott Danforth]

remember, there are 3 major systems for measuring octane

the RON (Research Octane Number)
the MON (Motor Octane Number)
and the AKI ( Anti-Knock Index) which is the (R+M)/2 method of the US

the manual specifically calls out the (R+M)/2 method when specifying 87 octane

as Jimmbo stated, the 87 AKI would be the same as 91 RON

many of todays cars have compression ratios in the 11 and 12:1 range, and some add turbos on top of that. the new Mazda motor is coming out with 16:1 vs the prior (current) 14:1

 

[maybe368]

So, if I had one of those high compression ratio cars,, I would run high octane fuels, wouldn't you? Preignition could destroy a high compression engine, right?...Mark P.S.. My Dodge Cummins is 19.5:1 and doesn't need spark plugs to fire and is also turboed. Go back and look at the compression ratios of old 70s Chrystler K cars. Technology has improved considerably...Also, in the old days, combustion chambers didn't come polished and perfect, they were in many cases built as cast. It was voids and undulations in castings that caused carbon buildup, that would glow hot and preignite the fuel. An average, non-mechanic could only run high octane fuel, where a mechanic might port and polish their combustion chambers...Also, modern cars have knock sensors that can detect and adjust to prevent pinging...

 

[BAYDOG225]

Might burn cleaner, less or no ethanol. Nothing to worry about. Just better gas.

There are no lower ethanol blends , only higher. 84 octane and 90 octane are the only non-ethanol gases. there is 10% ethanol blends, 15% and E85. Ethanol at 10% adds 3 octane to the mix, hence 84 becomes your 87, and 90 becomes your 93.

 

[Scott Danforth]

So, if I had one of those high compression ratio cars,, I would run high octane fuels, wouldn't you? Preignition could destroy a high compression engine, right?...Mark P.S.. My Dodge Cummins is 19.5:1 and doesn't need spark plugs to fire and is also turboed. Go back and look at the compression ratios of old 70s Chrystler K cars. Technology has improved considerably...Also, in the old days, combustion chambers didn't come polished and perfect, they were in many cases built as cast. It was voids and undulations in castings that caused carbon buildup, that would glow hot and preignite the fuel. An average, non-mechanic could only run high octane fuel, where a mechanic might port and polish their combustion chambers...Also, modern cars have knock sensors that can detect and adjust to prevent pinging...

comparing modern automobile engines to a modified industrial truck motor or 2-cycle outboard in a boat is like comparing turnips and elephants.

you may want to check your facts the K cars didnt come out until 1981 when the late Lee Iacocca introduced them (based on the VW block used for so many years prior in the Omni/Horizon front drives from 1976 on - VW rabbit based vehicles with a chrysler designed cylinder head and a carburetor vs the dual ohc VW motor and mechanical fuel injection). they were front drive cars with 8.6:1 compression ratios. are you thinking the LA motors or the B and RB blocks? Maybe your thinking the hemi line of engines.

if you want to argue mopar engine technology going back to the 50's or cummins engine technology, or high-end turbo cars starting from the 60's to today or even 440cc snowmobile engine powered go-karts....bring a couple of cases of beer. stop by. I grew up in a family that drag raced a variety of mopars as well as AMC and GM cars, built a variety of hot rods and street rods and my first ticket was 50 over in a gokart (got it talked down to a non-registered vehicle). Then I went on to work a Cummins for a while. if you want to argue octane, needs and benefits vs active and passive cam phasing and fuel/spark control, we can do that too

 

[maybe368]

xxx

 

[Bosunsmate]

The Octane Rating Scheme is often different in Countries outside of North America. Our 87 might be the same as your 91.

Wow, there's always something more complicated behind something that looks simple .
Working on hot rods, i wish i had neighbours like you Scott

 

[GA_Boater]

Another thread off the rails. How did this get past will using 3 gallons of 93 mixed with 3 gallons of 87 hurt my motor?

Closed. Lets talk about oil in the next thread. :facepalm: