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Getting a tune thursday. Wondering if 95 or 98 fuel is best to use and what timing? eg 95 with 8 or 10 degrees or 98 with 10 to 12 degrees.

Ultimate 98 is much dearer in the rural areas. is it worth it?

What fuel and timing would you use if you had a strong ea81?

I don't know too much about ea81's or tuning so I wouldn't quote me at all lol, but I do know that 98 fuel does give you more performance and a lot more distance, for example with my stock commodore i was running 95 for 2 years, swapped over to 98 and I get double the distance and more power.
There is a place off Burwood Highway that sell 100 octane, if I can find out where that might be better.

So your better off in my opinion to use 98, but hopefully someone else will give you better advice than I can.

Good luck with the tune and keep us posted on how it goes

yeah mate the 98 makes mine ping...95 is the go..

yeh, every engine is different.

100 no go for me- am in Central Vic and 98 is not even available all the time.

pinging on 98? could need the timing backed off a bit. I used to tune my high performance Lotus engine by climbing a hill in a high gears and backing off the timing until it didnt ping- that was the best timing setting.

Brado- try 2 degrees less timing.

But I am leaning towards 95. Some engines on 98 correctly timed would give great increase in power. not that I need it! lol

This thread could rage on for months.

some really boring reading

http://hunterdog.org.au/DiscussionBoard ... opic=593.0

http://www.scientificamerican.com/artic ... -premium-g

http://www.racq.com.au/motoring/cars/ca ... tane_fuels

98 unleaded is 151- 160 cents a litre down here in Bunbury/Australind I can't justify an extra 40 kms extra on a tank of fuel for that price.

According to the MV aka brumby owners manual (yes I do have one ) the motor is tuned to run on 90 octane or higher.

tune it to the way your wallet will feel when you are out on the open road

TOONGA

Read all 3 articles and came to the conclusion that it is unlikely that any higher octane than 91 is of any great benefit.

Which has aswered my question. I'll fill up with 91 and get it tuned at around 8 degrees BTDC.

TOONGA wrote:This thread could rage on for months.
TOONGA

Must..resist...posting...but can't...

Tune for the lower fuel, but in summer and maybe when towing, if available, and you're feeling generous, try the 98.

I have a standard ea81 with 5 speed gearbox and 14 inch rims with 27 inch mud tyres. i always use 98 ron fuel on standard tune up and rarely get less than 600klm`s from tank full. My weekly driving includes offroad/around town & highway cruising. Car has done around 270,000 k but does get major servicing every 10,000 k regardless. Costs me around $300 every time,i do it myself,that way i know it gets done properly, but for hassle free motoring and very rarely anything breaking,why not.

mmmm, the site Toonga put up puts on a good arguement to not bother going over manufacturers recommendations....ea81 being 90 or more. 91 seems the way to go in reference to these sites.

But I know with my new Jumbuck ute that 98 or 95 gives heaps more power noticable with acceleration and less fuel used at the pump. Very noticable.

Hence the thread. I think tuning to 91 is the go. Then swap octane to see if there is any extra kms to a tank and if it runs ok.

Interesting about the Jumbuck - I tried various fuels in my NA Foz, and could not see the difference.

Now I always advocate PULP in older cars, but personally have seen the difference in later models with ECUs. Turbos are the exception.

The 'campfire discussion' concluded the ECUs will adjust the timing to suit the fuel.

sven '2' wrote:Must..resist...posting...but can't...

Tune for the lower fuel, but in summer and maybe when towing, if available, and you're feeling generous, try the 98.

You are quite welcome to have your say this is an open forum

TOONGA

TOONGA wrote:98 unleaded is 151- 160 cents a litre down here in Bunbury/Australind I can't justify an extra 40 kms extra on a tank of fuel for that price.TOONGA

try it with a mercedes that cost 150 to fill (using 91) and gets 500 to a tank if your lucky

you are using the fuel tank that looks like a fuel tank or got another hidden somewhere? Isn't the rule of thumb with metal tanks avoid ethanol blends? NSW state government has made some declaration all standard octane must be at least 10 poo cent ethanol so to avoid some organic distaster in my metal tanks mowers etc and Vort I use minimum 95 with the understanding it does not contain ethanol - same in WA ?

You already have said it with tuning - same as your Lotus. I used to use those concrete lane dividers as a feedback - rippin' down the road at 90mph

Steptoe- dont know if you are refering to me or not- cant make out you post fully.

Inside my tank is all the electrics. the alloy monocoque chassis under it is the tank, one single one- 50 litres.

To my knowledge United service stations are the only ones here in Vic with ethanol. My previous engine- VW ran crap on it. Its a good question though.

I'm finding this topic interesting.

When you use 98 make sure you retune it, otherwise it is likely it wont do anything, except ping. 98 tuned well should be better than 91 tuned well.

I hear you Brumby Kid, an have been on the same page with this subject until recently.

Toonga's links earlier in the thread make for very interesting reading.

http://hunterdog.org.au/DiscussionBo...hp?topic=593.0

http://www.scientificamerican.com/ar...tion-premium-g

http://www.racq.com.au/motoring/cars...h_octane_fuels


They mount an arguement based on revenue raising by selling higher octane fuels, eg the suggest the word "premium" means to buyers- better, more power etc. There is as it seems a good bit of marketing here. It also seems clear to me that I should tune to 91 and if towing try 95 to seek if there is a 'real' difference.

The other point is that every engine is different. My jumbuck and its improvement in economy and power might not be the case with the EA81- a totally different engine in every way.

Now they have premium diesel. I run a i30 diesel. I tried this fuel last week. Didnt seem to make an iota of difference. But my friend who has a Navara 4WD ute diesel swears by the improvements.

Going higher octane on my EA81 seems a good way to waste cash. But I like the discussion anyway.

I've been running 98 in my EA82 these last few weeks, definitely notice the difference to 91. About to advance the timing to 12 later this week as well to see how much of a difference it makes.

Hey mate, i had an 85 Brumby EA81 with 220,000 kays on the clock. Did some research and found that if you run them at 10 degrees you can run the 98 etc. Mine ran spot on and with no flat spots or pinging. If the engine is tired you can run them up to 12 degrees but that may cause heating issues. Strangley though, i tried E10 on one trip and the car ran better with slightly better throttle response and far better fuel economy. I never ran it again because i wasnt sure what corrosive damage it did long term which is a shame because if i knew 100% that it was fine it would be my fuel of choice.

Tweety wrote:It also seems clear to me that I should tune to 91 and if towing try 95 to seek if there is a 'real' difference.

Tony it might not be a performance difference but the higher octane in warmer weather while towing may not cause the pinging that 91 could induce.

Timing the engine for 98 will mean that you're stuck using that fuel ALL the time, go lower when tuned for 98 and you've got some issues at hand. Tune for 91 or 95 and you can use 98 without an issue, you may not get more performance out of it but it could look after your engine in the long run from the damage that pinging induces.

Plus as you're planning to do the golden lap someday, 98 is not always available all the way around from what Subarino was saying when I caught up with him last year.

And I think you've answered your own question in an earlier post, but yes, this topic is always interesting!

I run 91 in Ruby Scoo, but I reckon a bit of 95 or 98 in the tank would have been a benefit in the heat...

For those running tired EA81s and EA82s - the reason why you'll notice a difference in better fuels is due to their reduction in the ability to pre-detonate, thus the carbon build up in the combustion chamber doesn't induce detonation before the ignition system wants it, it might be minor but it saps performance from the fuel without the tell tale sign of the little leprechaun with the hammer in your engine, a hot day and a load will though!

Cheers

Bennie

El_Freddo wrote:Timing the engine for 98 will mean that you're stuck using that fuel ALL the time, go lower when tuned for 98 and you've got some issues at hand. Tune for 91 or 95 and you can use 98 without an issue, you may not get more performance out of it but it could look after your engine in the long run from the damage that pinging induces.

Exactly. You cant use a fuel with a lower octane than its been tuned for without risking pinging.

So tune for 91, use 91, 95 or 98.
Tune for 98 use ONLY 98.

Of course this doesnt apply to cars where the ECU controls the timing.

Brumby Kid wrote:When you use 98 make sure you retune it, otherwise it is likely it wont do anything, except ping. 98 tuned well should be better than 91 tuned well.

Shouldnt be a prob...see above

steptoe wrote:you are using the fuel tank that looks like a fuel tank or got another hidden somewhere? Isn't the rule of thumb with metal tanks avoid ethanol blends? NSW state government has made some declaration all standard octane must be at least 10 poo cent ethanol so to avoid some organic distaster in my metal tanks mowers etc and Vort I use minimum 95 with the understanding it does not contain ethanol - same in WA ?

I'm not sure but i thought the only prob with ethanol blends was with some of the rubber seals. I've been using E10 for years with no probs.

In fact on the recent trip to Robe twice i paid over $1.60 for 95 octane. When i got back to melb i filled up with E10 (95 octane) for $1.37 minus 4c docket discount = $1.33.
Thats a saving of ~30cpl for basically the same fuel!

be aware of all the hype that oil companies spread about alternative fuels...they're competitors! If you trust multinational oil conglomerates to be truthful, honest & upfront....