Premium unleaded premium?

[NickZ]

Was 98 widely available back then? Or are you talking about the 91 <> 95 price differences?

Yep just like now all the majors had it - Shell Optimax (98 RON) was 8.8c a litre more than normal 91 ULP. I used to fill up my old civic with it as it ran better with it.

95/98 isn't as widely discounted as normal ULP. So the gap between it and 95/98 opens up on big discounting days.

At Shell the gap is always the same regardless of whether its tight ass tuesdays or rip-off thursday. Can't comment on the other brands though.

Will have to check, but I think the vast majority of cars for sale in Australia must run on 91 or 95RON fuel. Even the Golf Gti and Polo Gti will run on 95RON with no issues.

True, but the proportion of 98RON cars on the road and for sale now versus back then is higher. And the Polo GTI runs like shyte on 95RON, compared to 98RON IMO so even though it can take 95RON I wouldn't use it

[pologti18t]

True, but the proportion of 98RON cars on the road and for sale now versus back then is higher. And the Polo GTI runs like shyte on 95RON, compared to 98RON IMO so even though it can take 95RON I wouldn't use it

Well, there are a higher proportion of cars that run "better" on 98 than 95 than there used to be. Will have to check, but i am not sure they are allowed to sell a car in Aus that ONLY runs on 98RON (can't use anything else).

My PoGo runs fine on 95 if using the standard map.

[gerhard]

So, to sum up... stop whinging about petrol prices. It wont change anything and will most likely give you an ulcer

My PoGo runs fine on 95 if using the standard map.

So which camp are you in?

You criticize people who whinge about prices (which I agree with), and then you effectively whinge about the price of 98 by using 95 (which I think is only acceptable in an emergency).

[pologti18t]

So which camp are you in?

You criticize people who whinge about prices (which I agree with), and then you effectively whinge about the price of 98 by using 95 (which I think is only acceptable in an emergency).

Did I whinge? Or are you reading something in between the lines

I just said that the Polo Gti will run on 95 or 98RON (says so on the petrol flap).

[tdi guy]

As you are aware, high compression engines deliver more power, with or without additional inlet compression (e.g. turbo- and super-chargers). The high performance VW engines have higher compression (more than 9:1; e.g. 1.6l = 10.5:1; the 2.0FSI =11.5:1; my 1.4TSI = 10.5:1).

91RON is designed to ignite with lower compression motors. 98RON is designed to work with higher compression engines without pre-igniting (ie detonating at the wrong stage of the four-stroke engine cycle). 91RON will explode at lower compression rates (with less power). 95RON is in the middle there. Modern engines with electronic management systems can adjust the ignition timing to allow for lower octane fuels (eg 95RON and 91RON). VWs do this to work with 95RON... don't know whether they are designed to adjust for 91RON. Other cars also do this (such as Corollas, which work with 91RON but also with higher octane fuels).

Perhaps 98RON is more refined or has more additives to suit the higher compression engines. However, I wonder whether this accounts for the price differential. It seems unlikely the manufacturing/delivery costs increased for Shell by 3c to justify the increased margin (10 to 13c). I expect it is a marketing decision... just like closing pumps mid-week!

TG

[Kai]

I feel the difference in car power when i use unleaded vs premium.

[Treza360]

I still think that BP is the dodgiest as they only sell crappy ethanol blend as their regular unleaded and then Ultimate at 13c more expensive. However the price of the ethanol is the same as what the 95 regular unleaded is at Shell. Also I love how they say that petrol is back around or under $1 a litre however once again it's the ethanol crap and not propper petrol!
Shouldn't this thread also be in the fuels and lubricants section?
Cheers,
Trent
Edit: As I've never put anything but Premium in the R and don't intend to I don't know how it would feel running lesser fuel, but I know that in my old Magna if I put regular unleaded in it, it knocked something chronic. However with V-Power there was no knock due to the better quality. So whilst people always make fun of those who put the higher quality petrol in their bomby cars it does actually make a difference.

[gerhard]

Don't forget also that we have had Premium/95/regular fuels for a very long time.

It's just that we used to call it Super and Standard. For a while in the past you could swing a lever on the bowser and blend your own mix at 25/75, 50/50, and 75/25 in addition to the standard and super.

From memory, a large percentage of engines called for Super and would of course run on standard but ping unless the timing was retarded to suit.

My 202 with 149 high compression head, 13/4" inlets, port & polish, cam, dizzy, extractors, 3 x 1 3/4" SUs definitely needed super Not sure what the compression ratio was, but it was a hell of a lot higher than a standard 202

[Kai]

Pinging can happen alot without you even knowing.

If you can actually hear pinging. Its really really bad.

[pologti18t]

If I remember correctly standard leaded was around 87RON and Super started around 98RON and was reduced to around 96RON by the time leaded fuel was phased out.