What RON octane gas for a 1987?

[Kiwi Bloke]

In the UK, Oz and here in NZ, gas octane is the RON figure. In the US, your octane figure is the (RON+MON)/2 figure.

The highest octane gas here is 96 RON. Does anyone know what US octane that translates to, and whether it's suitable for any 1987 that I hope to buy? (The other available gas is 91. Holden Commodore V8s here use the Gen3 GM 350 engine, and they're happy with 96 RON, but that could be because of a different state of tune.)

Regards,

Adrian

 

[rrubel]

87 takes R+M/2 of 91 here in the US, which is mid-grade (87/89/91/93 is what's commonly available). So you should be more than fine with 96. Isn't that what the WRXs and Evo's take?
[RICHR]

 

[Kiwi Bloke]

Thanks for the reply! Yes - all of the turbo-nutter-b@stards use 96. I guess that 91 RON is too low, though. Would I be right?

Adrian

 

[Moonunit 451]

No, I think it should be OK. I'm not certain of the 87's but my manual (86) states 87 octane acept in some areas where you can run as low as 85. I run 87 in my low compression 383 with no problems.

You WILL need to know if there are any mods to your car that would requirre higher octane fuel. Lots of folks even with the older vettes run the premium fuel, but it is not neccesary for a stock application.

 

[Kiwi Bloke]

So I suppose it's really the old seat-of-the-pants bit. If it pings, then 91 RON is too low!

Thanks for the advice.

Adrian

 

[rrubel]

Moon, while 86's only need 87, my book says 87's need 91. Not sure what changed; compression ratio was the same.

I'd say 91 RON is too low. The cars do have knock sensors, so you might drop some power but you shouldn't damage the engine like on older SBCs. Might not even hear it ping.

The turbo cars that require 96 RON down under use 93 RM/2 here with no problems, so you're safe. You could probably, if you're low on cash, fill half a tank with 91 and half with 96 and be about right.

[RICHR]

 

[Kiwi Bloke]

Cool. 96 RON it is, then. Just another thing to cross off the list before I come over to buy a 1987 in Sept 2006

Boy this is fun - planning to realise a 20 year dream, in two years' time.

Adrian

 

[rrubel]

Hey - are you going to have to RHD-convert it, or does NZ not follow the same rules as Australia?

20 years is a long time to dream... but it's worth it!

[RICHR]

 

[Kiwi Bloke]

20 years *is* a long time!

Any LHD import to NZ needs to be converted to RHD **unless** it was first registered over 20 years before it arrives at the NZ port. My financing matures in April 2006, so if I leave it until later in that year, I should be able to get an early 1987MY.

Unless they change the rules on me. I plan to fly over after choosing the right car, buy it, drive around for a couple of weeks, then ship it home.

That's the plan, Stan!

Adrian

 

[craig0ry]

that is too cool, all for a vette! best of luck man!

 

[vader86]

No L98 should need more than midgrade octane, 87s can use the low octane but you should check for ping when you use it. If it doesnt ping then always use that octane.

 

[Kiwi Bloke]

This is where I show a dreadful lack of knowledge (which I will definitely improve upon, honest):

Which years did the L98 engine cover?

Adrian

 

[Moonunit 451]

This could go on for a while :L I think L98 is 85 - 91. The only thing that I'm aware of that changed 86 -87 was the move to aluminum heads in parts of 86 and all of 87. More changes in the heads, D-port aluminum, and compression (?) came in 88.

I know there was a point where the compresion was increased and higher octane ratings were required, but I thought it was around 92. Just discussion. You got LOTS of time to get all the info you need

 

[Daryllawman]

My 88 owners manual calls for high octane only.....

 

[rrubel]

Ah. And that explains the '87 versus a newer model... Sounds like a great plan!
[RICHR]

 

[Vettefan87]

When I called Shakers about my motor they asked me the compression ratio and I told them 9.5:1, and they immediatly asked me if I had run regular fuel in it. They said anything with a compression ratio of 9 and higher, premium fuel is required. Anybody else ever hear of this?


Justin

 

[vader86]

Premium isnt even required until you get a little over 10.0, LT1s generally need the 92-93 octane but some people get away with the 89.

9.0 doesnt need more than 87, 9.5 in general would do better with 89 (emphasis on 'in general') but its a gray area and some cars would do just as good on 87.

What you want is the lowest octane you can use without getting ping, thats going to produce the most power. If you run 93 octane in a 9.0 N/A motor, youre costing yourself power.

 

[Moonunit 451]

What you want is the lowest octane you can use without getting ping, thats going to produce the most power. If you run 93 octane in a 9.0 N/A motor, youre costing yourself power.

Right on, and money

 

[Hib Halverson]

RON or research octane number and MON or motor octane number differ in how the fuel is tested for its antiknock rating. The (R+M/2) rating used here in the states was an attempt by the U.S. government to level the playing field for refiners and consumers as far as how gasolines are rated.

The problem with "translating" that figure is you need to know either the the MON or the average as well as the RON.

That said, in my experience, a 96-oct fuel rated as RON is probably going to be fine in an 87 as, from what I've seen over the years, research and motor numbers for gasolines seem to differ from 5 to 10 numbers so, you can figure the R+M/2 octane of a 96 RON is somewhere betwen 91 and 93.5.

 

[Kiwi Bloke]

Thanks for the advice, everyone! I appreciate it.

Adrian