The Off Topic Thread.

[k31th]

exactly. I see the price, think I need petrol and buy it anyway

[ROB83R]

You don't notice it till you're filling the Prado with 180L of diesel @ $1.32. I found a servo locally that is 10-15c cheaper than anywhere else and it's a brand name too. I only use their diesel cause it's one of the best. 

[k31th]

I might think about 180L, but ~60L at most, it's a big from me

[Puffwagon]

Yeah I suppose if I used heaps of fuel I'd consider finding cheaper options. 

 

I currently use less than half a tank per week.

[ROB83R]

It's actually cheaper to do $50 at a time. Less weight means a fuel saving. Been trying it in the falcon too. $20 at a time which is about 13L roughly brings the economy down to bareable. I would get 450 out of a full tank. But now I reckon out of the 52L I've poured I've come close to 500km. I'm closer to 10L/100 now than the 14.1 the dash says. 

[MattyP]

Yeah mines been really playing up with dash economy vs actual economy, and a misfire at idle occasionally and really light loads, on any fuel. I like my e10 a lot, I can't justify the extra 10kw for a 20% price hike. I even run the misses wrx on 95e10 (where available) or 95 premium. 98 is just cents wasted out the back 

[ROB83R]

I agree. I've got no choice but till I upgrade parts. 

The g6 might need a quick service. Or a touch up tune. Do you only use united? The ethanol content might change causing them problems. 

[Puffwagon]

I've had a different experience tuning with 95 vs 98.

 

Granted it was with a different engine but it had a very similar compression ratio (8.4:1 iirc), slightly higher dynamic compression (180 psi) and ran a gt35r, a 0.82 rear housing and a large external gate.

 

3 octane points was not insignificant and allowed for 20% more timing.

 

If you see little to no gain using 98 over 95 then I suspect your car has been tuned for 95 or runs a super safe 98 tune that pulls timing regularly when run on less than 98.

 

This is often the case when you pay for a tune. No sensible tuner wants a car at the ragged edge. Go look at jets tuning thread to see how he felt about taking a stock motor over 500rwkw despite his ability to control knock and fuel. Yes that example is timing vs mechanical but you get the drift. 

 

Baring faulty parts a misfire at idle is caused from either; running lean, a too small/insufficient plug gap, incorrect cam timing at idle or too much ignition timing at idle. Bad fuel will cause a misfire at idle too but that seems highly unlikely in your case.

 

Oh I almost forgot, water out of suspension can create intermittent misfires.

 

Fwiw I could run as lean as 15:1 at idle with about 7 degrees btdc but needed 13.7:1 to run 15-20 degrees btdc without misfiring in my other car. 

 

I tune my ford to the limits of 98 and would not consider using 95 unless 98 was not available. 

 

Sorry for the novel fellas but hey, it might come in handy for someone one day.

[ROB83R]

Hey puff, is there a difference between 95 octane unleaded vs 95 octane ethanol blend? 

I think this is the reason for how his car was tuned better than 98 instead of the safe 98 tune you speak of. His e10 tune is very close to the 98pulp power levels you'd expect from a g series. 

[Puffwagon]

Yes there is a chemical difference. 

 

I don't agree but show me data and I'll change my mind. 

 

If there is a temperature difference in the burn from various fuels despite the same burn rate then there will be an advantage.

 

What I will say is that our motors are fairly identical and the main reason you will see large disparities in power output comes down to the dyno operator.