STE.W.

Ok, before you start slating me for asking a question regarding costs. I know the score, I run a big thirsty Leggy Turbo estate that uses $hit loads of fuel.

Optimax in our neck of the woods is £ 0.86 / litre.

Full tank cost approx £ 40.00 to fill.

In the past I have used NF and still carry a bottle around int boot just incase I get caught short

My question is.

Due to the costs of Opti at the moment, would there be any financial / performance benefit for me to start filling up with 95 ron fuel and add the usual 1ml to 1ltr mix of NF ??

My Leggy is mildly modded (ecu, exhaust, 15 psi etc) and have always used Opti where possible.

At the moment I'm thinking fill up with 95 and add NF but would like your opinions on the above.

Thanks in advance.

Ste

The_Judge

How much is 95RON where you live? Working on 80p/litre, assuming you fill up with 50 litres, and that you'd use 1/6th of a bottle of Race each fill-up at £13 a bottle...

Optimax = £43

95RON UL (£40) + 1/6th NF Race (£2.17) = £42.17

Cost wise, it's cheaper to go with UL + NF Race. Whether that would equate to the same RON value as Optimax alone, pass. However, here's an equation for you...

Optimax + NF Race + 16/17psi boost =

STE.W.

The Judge,

Thanks for the reply fella.

I think Shell 95 ron where I live is 78p / ltr so it would be cheaper to add Nf to that.

What about the actual ron rating for the 95 stuff after adding NF would it be the same / better than Opti ??

Oh yeh and NF + Opti will Equal 16-17 psi in mine too but you forgot to factor in the new gearbox and internals of me engine

Thanks again mate.

Ste.

The_Judge

I think 95RON UL with the recommended dose of NF wouldn't be quite as high as Optimax, which is supposed to be 98.6 if you're lucky. You could always add more though. But then I suppose if you have to add more, it kinda defeats the whole point of the exercise here, so you may as well use Optimax...!

Turbo_Steve

Save money by turning the boost down?

STE.W.

Thanks fellas

You two are like the angel and the devil on each of me shoulders.

Ste.

The_Judge

Turbo_Steve

LOL

James_TypeR

i have a question regarding fuel

ive always filled mine up on Super Unleaded (97RON)

my friend has a scooby and runs Unleaded...(95)

can this damage the engine? or will it just not run as good on boost etc?

Unleaded costs 76p/litre here and 80.2p/litre for SU

The_Judge

Depends on whether his is a UK or JDM.

If UK, and NOT modified boost, then he should be OK running it on NUL. The ECU should be capable of negative knock correction to prevent it from detting, and would limit boost if things got too bad. However, the car wouldn't feel as fast to drive as if he used SUL/Optimax.

If UK, WITH modified boost (ie manual boost controller), then NUL's a bad idea. The ECU may not be able to adjust the timing enough to cope with the increased boost/**** octane level of fuel, and won't be able to limit boost if things get too bad, as it has lost control of it. Det is just around the corner.

If JDM, whatever the level of modification, his engine's a ticking time bomb, waiting for the right time to grenade itself. Seriously, if he's running NUL, and is driving it in the manner God intended, it's just a matter of time. Get him to buy a Knocklink, and soon after you'll no doubt start a thread saying "My friend's just fitted a Knocklink to his JDM <whatever> that he runs on 95RON UL, and the red light keeps flashing..."

James_TypeR

yeah his is a standard UK turbo 2000 Classic, no engine mods tho, he is looking at getting a decat downpipe etc tho...will this start to sway things in the MUST use SUL direction?

Turbo_Steve

Yeup.