[Hairy]

Gday,
I recently had a pinging issue with my G13ba engine which was resolved by retarding the timing a little.
During the online discussion someone (gwagensteve) suggested trying 98 octane fuel.
last time I topped up the tank I used 95 octane as thats all they had and it seemed to give me a huge power increase.
My question is.......what difference, if any does it make to your engine.
will it run hotter? Burn plugs or anything?
Are there any negatives?
I used to run it in my V8 Calais and Lancruiser and it probably worked out cheaper if anything. ?......
Cheers

[russgt]

No negatives except for more initial expence. But if you are getting better milage and better performance its all win!

[atari4x4]

pretty sure that was me, 98 is the future

the higher the octane number, the more compression the fuel can withstand before detonating/igniting = bigger bang = more fasts.

[Hairy]

Thats good to hear......I haven't had a chance to compare mileage yet but in other vehicles it was better.
even if its a little dearer the power difference would make up for it I reckon.......

Cheers

[russgt]

In Japan standard fuel is 102 ron. America is 93 AKI Ron which is equal to our 98. Our fuel is old tech! Still runs well in my car however so i still use it.

[Gwagensteve]

Myth much there russ?

Our fuel is rated RON
US fuel is rated MON

U.S. fuel still doesn't match our 98. I think is compares to our rating at about 97. Their premium is 91 octane MON. Regular is 87. I never saw 93 MON in 6 weeks in the southwestand I've never heard of it.
Japan has 100 octane, but it's not "regular" and it's not widely available.

There is no point using higher octane unless your car is timed or can adjust for it. Otherwise the power is just disappearing down the exhaust. That's because higher octane burns longer.

Steve.

[russgt]

Gwagensteve wrote:

Myth much there russ?

Our fuel is rated RON
US fuel is rated MON

U.S. fuel still doesn't match our 98. I think is compares to our rating at about 97. Their premium is 91 octane MON. Regular is 87. I never saw 93 MON in 6 weeks in the southwestand I've never heard of it.
Japan has 100 octane, but it's not "regular" and it's not widely available.

There is no point using higher octane unless your car is timed or can adjust for it. Otherwise the power is just disappearing down the exhaust. That's because higher octane burns longer.

Steve.

Oops. Sorry.

Some still refer to their fuel as RON though. Thats what can confuse people.

[atari4x4]

Gwagensteve wrote:

There is no point using higher octane unless your car is timed or can adjust for it. Otherwise the power is just disappearing down the exhaust. That's because higher octane burns longer.

why is it that i can make a noticable difference between 91 & 98 in both power & economy, without doing any adjustments... that's been in both my vits?

[Marko_SJ]

atari4x4 wrote:

Gwagensteve wrote:

There is no point using higher octane unless your car is timed or can adjust for it. Otherwise the power is just disappearing down the exhaust. That's because higher octane burns longer.

why is it that i can make a noticable difference between 91 & 98 in both power & economy, without doing any adjustments... that's been in both my vits?

Are/were they knock sensed?

[Gwagensteve]

Pretty sure h and j motors are knock sensed, so yes.

[atari4x4]

nope, no knock sensors in either SV's... where's macdaddy when you need him,, he loves the good stuff.

i know the casting is there in the back of the H20a but blank. i assume there is a blank in the j20a for the knock sensor as i think by the SQ420 it got one. they changed the Cam Postion Sensor so it take a g16b CAS style of sensor rather than the integral unit that was in the SV420.

[Marko_SJ]

I did a test with premium vs regular unleaded with my commodore when I first got it.

I think I got 600ks mixed to a tank, or close to it with 98. Before that I got around 540 mixed driving using regular unleaded, doing pretty similar cycles.

It wasn't worth the extra 30% increase in cost for me. I don't think I felt much increase in power (however I don't use it anyway).

[monley]

In my turbo taxi I noticed a big difference in power and ecomny between BP 95, 98 and gull 100. I get around 440kms to a tank on 95, 470 on 98 and 500 on 100. Imo it's worth the extra dollars for better fuel...

Shame 100 octane fuel isn't readily available in Aus

[christover1]

My Vit on both its engines (1 Vit and now Baleno/Swift) always felt like it ran better on 95/98, than 91.
Could not "feel" any difference between 95 and 98.
I chose to stick to 98 because I read of its claimed fuel system cleaning properties.
Price is irrelevant as too much of rest of a car eats so much money anyway.

[Gwagensteve]

95 and 98 are the same product. There are only two grades of fuel blended- ULP and PULP. (91 and 98) 95 could be 98 octane, but it won't be less that 95 it could be off spec 98, it could be 98. Afaik, 95 will "clean your fuel system" just as well as 98. (I don't even know what that means but I bet the marketing departments of the fuel retailers do.)

[buzbox]

Check this out --> https://www.youtube.com/watch?v=eHE5wo6XPf4

[henno]

Gwagensteve wrote:

95 and 98 are the same product. There are only two grades of fuel blended- ULP and PULP. (91 and 98) 95 could be 98 octane, but it won't be less that 95 it could be off spec 98, it could be 98.

I can almost guarantee that is the case. In fact, I should tap one of my old refinery contacts on the shoulder and ask them to confirm.

Just to throw a spanner in the works compared to everyone above, I have experienced no noticeable change in power or fuel economy in my SQ420 no matter what fuel I use. The only thing I have ever noticed at all is a reduction in pinging when flogging it in soft sand at straddie last year, although that could say more about a bad belly of 'island fuel' in the first tank more than the benefits of the premium I put in for the second tank, as the J20 shouldn't ping anyway.

[Hairy]

buzbox wrote:

Check this out --> https://www.youtube.com/watch?v=eHE5wo6XPf4

Not a bad video...........Cheers

[Gwagensteve]

Regular Australian 91 octane fuel should be pretty long lived. I've only ever had one bad batch of fuel- my g16b Sierra ran on it fine, but none of my power equipment would run on it. 98 has a very short shelf life apparently.

[christover1]

From the owners manual that came with my 93LWB Vitara.
I won't use E10. It is not recommended by Suzuki on the E10 Aus web site,
even though it says ok in the manual.

[henno]

Gwagensteve wrote:

Regular Australian 91 octane fuel should be pretty long lived. I've only ever had one bad batch of fuel- my g16b Sierra ran on it fine, but none of my power equipment would run on it. 98 has a very short shelf life apparently.

You're probably right. I was only throwing out wild possibilities as that was literally the one and only time I have ever noticed a difference in engine characteristics between tanks of fuel and doubt it had much to do with the increased RON of the second tank.

[christover1]

Fuel quality was a definite issue with my carby Sierra.
No idea if it is as critical on efi.

[alien]

I can run mine on 91 in winter without issue, but in summer it'll ping on 91 under heavy load. On 95 it may ping now and then at highway speeds and never at all on 98.

So i just run 98 year-round.

[Seth2013]

never run anything but 98 in anything I own, unless there is not 98, then 95. but everything I own is EFI

reason being - 996cc 2001 daihatsu handi I owned, 95 octane - noticeable power increase. 98 octane - not much more power than 95, but up to 10% better fuel economy. interestingly after changing to 98 octane, I looked up what plugs were recommended by the Japanese Denso website, they were a different/higher heat range to what the Australian site recommended - so I swapped to the ones recommended on the Japanese site, and got more power again. (and the power increase was real, I used to accelerate up a hill from a dead stop, and check the speed at the top - genuinely 12 km/hr faster at the top with plugs and 98 octane)

having said that, I ran 98 though the work Yaris and it seemed to make no difference, however that car is rubbish.

[alien]

I think the reason for that is that high compression engines benefit more from higher octane...Although the yaris NZ and the diahatus (toyota) 1KR are both 10.5:1 (not overly high).

[303zuke]

christover1 wrote:

From the owners manual that came with my 93LWB Vitara.
I won't use E10. It is not recommended by Suzuki on the E10 Aus web site,
even though it says ok in the manual.

You don't get a choice, there is no such thing in Australia as E10 anymore as a separate product. ALL grades of petrol sold in Australia MAY contain up to 10% of ethanol, and I think it has become mandatory for the petrol companies to blend ethanol into fuel to meet an environmental target for volume percentages, so the more E85 the revheads buy, the less the rest of us have to use:

http://www.environment.gov.au/topics/en ... rds/petrol

Anyway, is all good, as Ethanol raises the Octane rating of petrol!!

[henno]

303zuke wrote:

You don't get a choice, there is no such thing in Australia as E10 anymore as a separate product.

Interesting. E10 is certainly marketed at every petrol station around my area as a very separate (and cheaper) alternative to ULP.

So 95ron is likely 98PULP most of the time, and ULP is likely E10 most of the time. Considering the huge spread of price across the range ($1.12 for E10 this morning and $1.32 for 98, with ULP and 95 filling the gap) it's certainly a little eyebrow-raising.

[303zuke]

What the servos are marketing as E10 probably has the full 10%, while the ULP that ethanol avoiders are paying a premium to avoid could have only 6, 7, or 8% Ethanol.

[zukenutter]

What % of ethanol do they run in Mexico?

[just_cruizin]

All this talk about more power and better economy is fawled as unless the engine is designed to utilize the higher octane ie higher compression as mentioned earlier. What is the reason for the percieved improvements then, I would assume tuning issues in the first place limiting the performance with the ULP where as the PULP can accommodate the poor tune. If tuned correctly a standard G13 or 16 should perform the same regardless of fuel