Dodgy fuel - Caltex M4

[Bennoz]

Stop using 91. In any car. It makes baby Jebus cry.

The tightwad of cash you've just saved = less efficient burn = less kms per tank = saving gone.

[bjk]

Stop using 91. In any car. It makes baby Jebus cry.

The tightwad of cash you've just saved = less efficient burn = less kms per tank = saving gone.

I was under the impression that most passenger cars designed to run on standard fuel wouldn't particularly benefit from premium, due to the ECU not really being able to account for the difference or somesuch?

[dstocks]

Cars are generally detuned to cope with lower ron fuels, not necessarily designed for them. The higher RON fuels will still burn better and generally be better for your engine. Besides, what makes you think that most standard passenger cars have been designed to run on 91. If it was made in Australia, possibly, but more likely they are just a detuned overseas spec. If the car is made anywhere else then the standard octane level will quite possibly be different anyway. In Japan, their octane level is generally higher than ours, particularly in the cities. In the regions is is poor quality, but not necessarily that much lower.

[SchumieFan]

Quite the opposite bj... ecu's are computers mate! They calculate and adjust a/f ratios to suit...

Something with a carby would blindly add fuel - with added benefit of hp depending on the fuel sure... but there is no such thing as 'standard' fuel... hence the need for an ecu in the first place

[bjk]

:themoreyouknowrainbow:

[Daniel2019]

Nup. E10 makes even newer Mazda's upset.

95 or more please.

As Ben said you get a cleaner burn and more fuel economy from higher rated fuels.

[spetz]

Most cars have knock sensors too, so the ECU is then able to adjust the timing with 98RON and hence achieve more power.

Some cars don't have knock sensors though and as such the timing is set to cope with 91RON fuel

[Daniel2019]

You get all sorts of weird stuff from lower rated fuels.. Remember octane rating is the fuel's ability to avoid self ignition/ignition due to compression. The higher the rating, the more likely the fuel is to ignite at the ideal time.. which gives cleaner burn, happier engine.. etc..

Just put 98 in everything ffs.

[SchumieFan]

Looked at the ratings today as i filled up... "91 - regular octane... for some petrol engines* *check your manufacturer manual

95- for most petrol engines

98- premium - for all petrol engines"

[PHIL069]

FTO - Vortex 98
Galant - Vortex 98
Laser - Caltex 91 - with no ethanol - because race car

[Strkszone]

Most Japanese motor vehicles are tuned to run on 91 octane just fine. 95 is usually standard for European manufactured cars and 98 can of course be run in all petrol engine cars. 98 is more expensive in the long run, but it's better for your engine and increases performance. The cost difference I believe only amounted to something like $40 / 20,000km (or 1 year). A test for fuel efficiency was done by carsguide.

Using a Holden Captiva 7 CX they measured
11.9L / 100km (E10) vs 11.1L / 100km (91) vs 10.2L / 100km (98)

Meaning that:

$1.454 / L = $17.30
$1.474 / L = $16.36
$1.634 / L = $16.67

It is more optimal to run 91 in terms of short term fuel cost if... the price difference between E10 is less than 8 cents cheaper than 91.. and in addition 91 needs to be 13 cents cheaper than 98 in order to remain optimal. So if 98 is 13 cents more expensive than 91.. it is cheaper to just buy 98... and in general it's better to buy 98 anyway due to the fact 98 is simply a higher grade of petrol. It's better for your engine and the overall cost per year that you're spending is more than worth it.

http://www.carsguide.com.au/car-reviews ... Zxf7Pmqqkp

[SchumieFan]

:LNB:

[bjk]

:LN98:

EFA

[Bennoz]

Most Japanese motor vehicles are tuned to run on 91 octane just fine

Japan doesn't have 91 RON. 95 is their lowest, much like the rest of the world.

[Strkszone]

Most Japanese motor vehicles are tuned to run on 91 octane just fine

Japan doesn't have 91 RON. 95 is their lowest, much like the rest of the world.

But... it's on the internet... ..???

http://www.mynrma.com.au/motoring-servi ... e-fuel.htm

I always assumed only certain Japanese cars were designed to accept premium as a greater benefit as opposed to... Honda Civics/Accords/Jazz... Toyota Echo/Camry/Corolla/Yaris etc etc..? Then the upper spec ones.. Supra, S2000, NSX, Rotary Line, Evo, WRX... would benefit from premium grade petrol?

Edit: Also, just because they don't use it in Japan surely doesn't mean that the factory doesn't take that into account..?

[Bennoz]

The bulk of Jap cars that are imported for sale in Aus are re-tuned. Primarily to meet Australia's emissions standards.

[Strkszone]

Makes sense, thanks Ben.