Outer Limits 4x4 Board

HAs anyone tried this new fuel from Shell??

Its 100 octane with 5% ethanol.

mitsu say that all their fuel injected petrols can run on ethanol mixed fuel.

The bit that interest me though is the 100 octane.

Not sure if the NL 3.5 would be 'smart' enough to make use of it, as its designed to run on standard 95. But I can notice a small improvement when I run it on premium, so maybe its worth a try>

What do others reckon??

Probably not worth it. You should run any engine on the lowest, yes lowest people, octane rating it's designed for.

Having said that, the 3.5 may have a couple of knock sensors and be smart enough to extarct some more energy from the mix. have to ask a smart person....

its fishi wrote:Probably not worth it. You should run any engine on the lowest, yes lowest people, octane rating it's designed for.

How do you come to this conclusion?

If you are using a fuel of a higher octane rating than the engine is designed for all you are doing is sending unburnt fuel out the pipe.

Maybe I should have said "you should use the lowest octane rating fuel that will give complete combustion of the fuel/air mix without causing detonation".

its fishi wrote:If you are using a fuel of a higher octane rating than the engine is designed for all you are doing is sending unburnt fuel out the pipe.

Maybe I should have said "you should use the lowest octane rating fuel that will give complete combustion of the fuel/air mix without causing detonation".

Is that before or after I adjust my ignition timing?

Scott, notice I used the word "designed" in anticipation of your line of questioning.

You're over-simplifying the issue.

Any given engine is tuned to operate with a fuel of a given octane rating. Within limits, you can retune an engine to take advantage of higher octane fuel - typically by advancing the ignition, which generally leads to more power.

Modern engines designed to run on high octane premium fuel will also run on lower octane regular fuel by using a "knock sensor" to detect knocking and retard timing.

So, by your definition, which octane are they "designed" for?

Scott

Scott, I agree with all you are saying, you can adjust the timing to help adjust to different fuel.

This said also some high performance engines do run better on higher octane due to their high compression ratio and tendancy to pink on lower octane fuel. I had a turbocharged Subaru and it did not like 91 octane, I made sure i didn't give it a bootful with that tank!

Ah the joys of EFI computers a. Our old Mahindra Indian CJ4 Jeep with a F head was degigned to run on 87 octane but it went so much better on 96, less burnt valves, and much less pinking!

Cheers

I run the 100 ron shell in my Evo 8. Doesnt make much diff at all. Not too sure about economy figures because my right foot blows that out the window. Bp 100 is not far off though and will contain 0 % ethanol.

NJ SWB wrote:You're over-simplifying the issue.

Any given engine is tuned to operate with a fuel of a given octane rating. Within limits, you can retune an engine to take advantage of higher octane fuel - typically by advancing the ignition, which generally leads to more power.

Modern engines designed to run on high octane premium fuel will also run on lower octane regular fuel by using a "knock sensor" to detect knocking and retard timing.

So, by your definition, which octane are they "designed" for?

Scott

Using the "its fishi" defiintion of designed, an engine should be tuned to extract maximium power (not economy ). This is going to occur with a fuel of a given octane rating. Once you exceed (or reduce) that octane rating power will decrease. This is therefore the octane rating that engine is designed for.

ok in this case "designed for" is about compresion ratios yeah? the higher the compresion ratio the more stable the fuel needs to be so it can be ignited at the right time. the pajero (pick any motor you like) doesn't have very high compresion so it doesn't need 100 octane.

now with grant's evo 8 for instence it will make a difrence (although going from 98 to 100 won't be a big jump) i have seen a test where sevral cars were filled with regular unleaded and put on a dino then put on optimax and dinoed again the result the rover 25 saw no improvement but the wrx sti saw a 15 hp improvement.

Matt

Men

I've done some testing on this and on my runns to Perth (1000k round trip) I've found the higher the octain the petrol, the more money I save as the engine becomes more efficient and the higher the price of petrol the more the gap

To put a fine point on it $100 worth of PULP gets me further than $100 worth of ULP

Happily I also get more power to to overtake all those diesel slugs

Ado

Ado,

have you tried the new shell 100 though??

Ian

I hasn't appeared out here yet, but I'll give it a shot when it does

Ado

I'd check that it's not the same as Avgas, with a mix of lead. If it is, it will eventually block your catalytic converter with tetra-ehtyl lead. Cost lots to replace! Should be allright if you have a straight through pipe, or do a transplant with any heart pre 86, but I'd stick with pulp.

Overkill wrote:I'd check that it's not the same as Avgas, with a mix of lead. If it is, it will eventually block your catalytic converter with tetra-ehtyl lead. Cost lots to replace! Should be allright if you have a straight through pipe, or do a transplant with any heart pre 86, but I'd stick with pulp.

This fuel does NOT have lead as it is available from the bowser

Ian, I have tried all the PULP fuel from the different companies in my NL & TBH is a waste of money. Found BP Ultimate the best, with Optimax the worst. Results were slight improvement in performance, but hardly mind shattering. Economy; maybe an extra 10klm out of a tank. Tests were done on highway & city driving along with 4wding & towing my boat. Now use either the Shell 95 or Caltex Vortex (using discount vouchers). IMO, I wouldn't bother with Shells new stuff.

Cheers
Allan Mac

Allan,

Yeah I use vortex myself & found it OK.