94 ron

**Davestown** · 02-04-2014, 10:14 PM

I run normal juice in the van and whilst it is ok I can feel it lacking.
Can you mix premium and standard to achieve a value of 94 RON (the old super) and what would be the quantities if standard is 91 RON and Premium 98 RON for a total of 50 litres?
Dave
( AND I STILL ADD THE VALVE STUFF)

**HK1837** · 02-04-2014, 10:18 PM

If it is a proper 9.7:1 308 you really want 98. Earlier reds up to HQ and later blue and black are lower comp.
But mixing will increase. E10 ends up about 93-94 as Metho is about 110 or thereabouts and the 10% mix with 91 increases it by about 2 points.

**Big Rob** · 03-04-2014, 01:13 AM

Run 98 in everything! It's cleaner and doesn't have the 10% ethanol crap in it.

Christ! I run 98 in my lawnmower!

**wbute** · 03-04-2014, 07:00 AM

Lead was removed from petrol here in 87 or there abouts. It did lead to valve recession in heads in older cars. Lowered the octane as well causing pinging in higher compression engines.
There are lead additives you can buy to put in fuel. The best thing was to have hardened valve seats put in the heads and buy the higher octane fuel if you had a pinging issue.
If you don't have a higher compression ratio you won't gain anything from higher octane. But.... Don't use lower octane to premix two stroke fuel and not use it straight away.
Haven't heard of the zinc in oil thing?

**HK1837** · 03-04-2014, 07:39 AM

Older engines need zinc in the oil, many oils today are missing it.

**wbute** · 03-04-2014, 07:48 AM

But why? Just stick to the old adage of " change your oil every couple of years whether it needs it or not".

**HK1837** · 03-04-2014, 09:00 AM

Cam and tappets afaik. Modern engines generally are roller lifters or OHC.

**Dr Terry** · 03-04-2014, 02:43 PM

Originally Posted by Big Rob

Run 98 in everything! It's cleaner and doesn't have the 10% ethanol crap in it.

Christ! I run 98 in my lawnmower!

98 is no cleaner than standard unleaded (91 RON), that's the power of media advertising at work. It has a higher RON, that's all.

BURD is correct about zinc though, older engines with flat tappet cams, don't like the lack of zinc in the oil.

Dr Terry