Maarten
You are almost correct... but the aditive on the fuel is really alcohol.
Fuel here in Brasil is always a long,long history... so, let's go again...
TYPES:
All fuel is unleaded, it's use alcohol instead of lead...
The base mix for "gas" is: 76% gas + 24% alcohol
"Álcool" - In the stations we have the 100% alcohol! It's really popular here, cause it's cheaper than gas...
It's the commom Anhydrous or Ethil Alcohol, from sugarcane... never try to use (or drink.. heheh) it!!!
"Gasolina Comum" - low octane gas, base mix
"Gasolina Aditivada" - low octane, base mix + cleaning aditives
Each brand has it's own set of aditives and name... Shell V-Power, Texaco System-3,...
Indicated for use in modern EFI engines... The cleaning additives could remove the crap and rust in old engines and fuel tanks, what sometimes means carb problems and leaks...
"Gasolina Premium" - high octane, base mix + cleaning additives + anti-knock aditives
Each brand has it's own set of aditives and name...
For use in high compression engines...
ALCOHOL PROBLEMS
Yes, 1/4 of the gas is in truth ALCOHOL!
Problems with rubbers... maybe, I really don't know...
But fiberglass or epoxy "rust protected" tanks have problems... the alcohol dissolves the resin...
CARB ADJUSTS
Alcohol needs a fat mixture... so the foreign engines will run lean... but I think it's only a problem if the engine is already running too lean...
The fuel injecteds will manage this without problems... but if the engine is high than 10:1, is better to use "Premium"...
THIRD PART ADITIVES??
Well... today we have a big problem with falsified fuels... some distibutors buy cheap solvents and mix on Fuel... some do the trick putting more alcohol than indicated... so, be carefull WHERE you get the fuel... if possible, choose big gas stations in cities... the small stations on the road are all suspects...
regards
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Fernando&Carmen
Webmasters
www.xt600.com.br
[This message has been edited by Fernando&Carmen (edited 18 April 2004).]