Octane

[SmokeGrinder]

Just a random question really, what kind of Octane level gas do y'all use in your x's?

 

[X~FACTOR]

87 Octane. Anything more and you're wasting some $$$. Unless you have a Computer Chip that requires you to run Premium Gas.

 

[VairKing]

Yep good ole 87 is what the owners manual says to use, and is what everybody should use, unless you have any sort of computer mods...anything else is just a waste of money...

 

[SmokeGrinder]

I put 98 Octane gas in my SOHC today AKA Shell Optimax. its has a cleaning agent in it too.
it really does run better! you can feel it.

http://www.shelloptimax.co.uk/index.jsp

 

[VairKing]

I would NOT recomend 98 octane fuel in a stock motor! That just seems like a really bad idea to me...

 

[SmokeGrinder]

oh well i guess i will be buying a new SOHC soon i mean tons of people use this stuff on stock's

 

[03ExplorerSPT]

I use Chevron 87. It's cheap and it's what the manual says.

 

[sonik]

92 octane from Chevron.

 

[SmokeGrinder]

sonik,
would you put that in a stock?

 

[Alec]

If your computer isn't programmed for it, higher octane can actually damage the motor; even if the motor "feels better."

That being said, some cars sense what gas you put in and change their programs accordingly. My VW takes premium, but if you put in 87 it wont ping, you'll just have less power. Your 98 does not have this programming.

 

[SmokeGrinder]

oh well i will go back to normal gas next time

 

[Alec]

And BTW, higher octane gas does have more detergents and helpful additives; but only because higher octane gas makes things dirtier in the first place.

 

[SmokeGrinder]

http://www.shelloptimax.co.uk/index.jsp


http://www.shell.com/home/Framework...uels/testing_optimax_3011_1831.html&FC4=&FC5=

Can I use Optimax in my car or motorbike?

You can use Optimax in any engine which runs on super unleaded or unleaded. It is an ultra low sulphur gas.

 

[SmokeGrinder]

Can I run my stock ford Explorer 4.0 SOHC on this stuff?


Thank you for your recent e-mail.
I can advise you that Shell Optimax is suitable in all vehicles designed to run on Unleaded gas.
The octane rating of Shell Optimax is 98 which means it is the highest octane fuel currently available in the UK.
It is not just the octane rating that differentiates Shell Optimax from other fuels. Shell Optimax is a unique highly refined new formulation which burns more cleanly to give you smooth power delivery. It is able to do this because:
* as the gas with the highest octane rating in the UK it enables advanced modern design engines to work more efficiently thereby delivering more power
*it has the ability to remove performance sapping deposits left by other fuels from the airways of the engine
*it is free of the heavy constituents of gas that leave dirty residue in you engine.
The combination of these effects means that the fuel and air flow smoothly and quickly to the engine, burning more effectively to give you increased performance and a quicker response.
All our service stations including those selling Optimax can be found on the following website;
www.shellstation.biz
If you require any further information then please do not hesitate to contact our Customer Service Centre on our free phone number 0800 731 8888.
Kathryn Baillie
Customer Services
Shell U.K. Oil Products Limited
Rowlandsway House, Rowlandsway, Manchester M22 5SB, United Kingdom

Tel: +44 161 947 5523 Fax: +44 161 499 8088
Email: kathryn.baillie@shell.com
Internet: http://www.shell.com/uk

 

[Howard]

Here is what it says in the Ford supplied handbook.

"Unleaded fuel (95 Octane)

Higher octane unleaded fuel may be used without detriment but offer no significant advantage."


and on the back of the book it says.

"Unleaded Fuel (95 Octane)
Unleaded fuel 91 or 98 octane can also be used"

Make what you like out of that but I would only use 95 as recommended. Then if you have a problem you have cause for complaint.

 

[Alec]

Something to look into:

Octane rating in the US is different than other countries, I think they use a different calculation.

 

[SmokeGrinder]

let me ask my new buddy at shell

 

[OZexplore]

Ionly use 98 in australia b/c 91 makes some X's ping and there is no other choice it gets 27.5 mpg on the h/way at 110 kmph stock engine

 

[silver96]

man, where do you guys get some of this stuff?

All an octane rating is, is its resistance to detonation. Running a higher octane in an engine that doesn't need it doesn't do anything but waste your money, it won't hurt the engine at all. (assuming your not using leaded fuel to get high octane, then your gonna be replacing your cat's and 02's) Octane has nothing to do with how hot or cool the gasoline burns, or how much power it produces. In simplest terms higher octane burns slower and is more stable, where lower octane burns faster and is more volatile

98 Octane in Europe and Aus. isn't like 98 here as Alec pointed out. They use RON (reasearch octane number) which is generally higher because the test to determine the rating is more forgiving. We use RON+MON/2. MON stands for motor octane number and is generally lower because it is a harder test and more closely simulates real world driving. So we use a combo of both to get our rating where as they just use the inflated RON rating. 98 in EU and Aus. is like 93 here in America. If you have an OHV (which is 9.0:1 I believe) you could probably get away with 85 octane if you had to.

How do I know this? Ive had to do a little reading on it because Ive owned a few FI vehicles, and make my own high octane brew because its cheaper than race gas.

 

[Kadarom Douhrek]

Originally posted by silver96
In simplest terms higher octane burns slower and is more stable, where lower octane burns faster and is more volatile

Yes, and in an engine that isn't designed for higher octane the spark fires too late.
That means the fuel isn't completely burned when the exaust port opens, allowing still burning fuel to reach the O2 sensors and cat.

Do that for too long and you will melt them.