95 ron ok to use in 99 ron mapped car?
 

Hey guys, my blob sti has been mapped on Shell Vpower super unleaded 99 ron fuel and is pumping out 350 ish bhp.

After the recent fuel shortages i have had to resort to putting in some normal unleaded 95 ron from various differnt garages because there has been no super unleaded available.

Is this likely to damage the engine in any way? Or cause any problems?

The car feels and pulls exactly the same to be honest, cant notice any lack in power.

Cheers

no its not ok, you will more than likely melt a piston, if you have to use it drive off boost until you can find decent fuel.

Yes it can cause serious damage and quickly if you hammer it as you have implied you have by saying you noticed no power difference.

just go really steady there mate, off boost only...

someone else might know more about the technical stuff

A forged piston from a bike that suffered Detonation problems.
Attachment 67821

Your engine, your choice. I'd rather walk

What about octane booster, any out there that do what it says on the tin?

**** i had no idea. I only put £30 worth in as i have to go on the motorway wednesday. Yes would an octane booster do the trick?

Better than nothing i suppose but why didn't you at least put 97ron in? everywhere sells that.

I went round a couple garage near me and they honestly only had the 95 ron. i ended up using esson 95 ron. Im panking now! :eek:

Would octane booster help?

Silly question, but is Ron the same as octane??

yes mate

yeas, RON is the standard we use to indicate knock resistance i,e high octane.

And Lewisdj there has been mixed reports on octane boosters so i wouldn't like to say whether they work or which ones are better.

Every day's a school day :)

just stick below 3000rpm or off boost.. no issue..

Simon

Thanks for the advice, i know you know your stuff when it comes to engines :thumb:

Would you bother with an octane booster for peace of mind?

not if you can stick off boost or under 3000rpm until tank empty etc..

ok, well at least i should get a few more mpg driving it around like that for a while. cheers

As per the advice above ,it may be worth resetting the ecu also imho,as the engine ecu reacts to the lower quality fuel & retards the timing and reduces maximum boost from the turbo.In time the ecu should unlearn these setting once 97/99 octane fuel is used once more.Just drive off boost for now until tank is near empty then fill up with shell/tesco99

One thing to remember that Bob Rawle told me... it will take 3 tanks of the good stuff to dilute and get rid of the crap stuff. Bare that in mind when you get back onto the good stuff before giving it beans. That's why this weekend gone, I made a day out of getting Vpower from 30 miles away as I couldn't bare 4 tanks worth of trying to drive off boost on a TD04. :)

Toluene is your answer.
If you have a 60 litre tank and its full - siphon off 12 litres and replace with Toluene .
This will give you 100 octane fuel.
x= quantity of Toulene 120 RON
60-x = quantity of fuel 95 RON

(60-x)95/60 + 120x/60 = 100

x = 12 litres.

2 x 5 litre tins for 39 quid from http://stores.ebay.co.uk/TRADE-PAINTS-UK-LTD

Will still give you a overall RON 99.

Unfortunatly it doesnt just have a high ron it will effect the fuelling as it has a different stoich point so will run leaner. Still therefore wont match what it was mapped for. Therefore better to drive it gentle and keep off boost until it has a decent tank of fuel in it.

We've ran out of super unleaded in cheltenham too! The garages say there prioritising the crap stuff! I was like what about me! So had to put the crap stuff in. After reading this I don't want to drive :(

If it was my car I wouldn't even drive it without the good stuff in, even keeping it off boost. Is it really worth the risk of damage ?

RE octane boosters, personally wouldn't even entertain them.

+1 :cry:

Sometimes you don't have much of an option. Take my mate Jeff (Alcazar) for example. Has a 98uk car with a link ECU mapped for Vpower. Sometimes uses it for runs to hos French house, middle of nowhere. Petrol never mind super is hard to come by at time. Some of the octane booster in a tank is sufficient to make his car safe even on boost. Bulk buy and it isn't too expensive. Can't have two maps on his ECU which is a shame.

Just keep the thing off boost and you'll be fine

Mines been off the rd since wed, sat on my drive empty, am useing the sister in laws T reg fiesta :-/

Just think how fast your scooby will feel when you get back in it :thumb:

Have decided to buy a bottle of this:

http://www.halfords.com/webapp/wcs/s...egoryId_255221

or maybe some of this:

http://www.halfords.com/webapp/wcs/s...Id_255221#tab1

You guys are all making me so paranoid i just want to be on the safe side!

I did however read a very interesting article about adding toluene...

http://elektro.com/~audi/audi/toluene.html