Here's a direct quote for the EX35 manual:
"FUEL RECOMMENDATIONVQ35HR engineINFINITI recommends the use of unleaded premiumgasoline with an octane rating of at least91 AKI (Anti-Knock Index) number (Researchoctane number 96).If unleaded premium gasoline is not available,you may use unleaded regular gasoline with anoctane rating of at least 87 AKI number (Researchoctane number 91), but you may notice adecrease in performance.CAUTIONc Using a fuel other than that specified couldadversely affect the emission control system,and may also affect warranty coverage.c Under no circumstances should a leadedgasoline be used, because this will damagethe three-way catalyst.c Do not use E-85 fuel in your vehicle. Yourvehicle is not designed to run on E-85 fuel.Using E-85 fuel can damage the fuel systemcomponents and is not covered by theINFINITI vehicle limited warranty.Gasoline specificationsINFINITI recommends using gasoline that meetsthe World-Wide Fuel Charter (WWFC) specificationswhere it is available. Many of the automobilemanufacturers developed this specificationto improve emission system and vehicle performance.Ask your service station manager if thegasoline meets the World-Wide Fuel Charter(WWFC) specifications.Reformulated gasolineSome fuel suppliers are now producing reformulatedgasolines. These gasolines are speciallydesigned to reduce vehicle emissions.INFINITI supports efforts towards cleaner airand suggests that you use reformulated gasolinewhen available.Gasoline containing oxygenatesSome fuel suppliers sell gasoline containingoxygenates such as ethanol, MTBE and methanolwith or without advertising their presence.INFINITI does not recommend the use of fuels ofwhich the oxygenate content and the fuel compatibilityfor your INFINITI cannot be readilydetermined. If in doubt, ask your service stationmanager.If you use oxygenate-blend gasoline, pleasetake the following precautions as the usage ofsuch fuels may cause vehicle performance problemsand/or fuel system damage.c The fuel should be unleaded and have an octanerating no lower than that recommendedfor unleaded gasoline.c If an oxygenate-blend, excepting a methanolblend, is used, it should contain no more than10% oxygenate. (MTBE may, however, beadded up to 15%.)c If a methanol blend is used, it should containno more than 5% methanol (methyl alcohol,wood alcohol). It should also contain a suitableamount of appropriate cosolvents andcorrosion inhibitors. If not properly formulatedwith appropriate cosolvents and corrosioninhibitors, such methanol blends maycause fuel system damage and/or vehicleperformance problems. At this time, sufficientdata is not available to ensure that allmethanol blends are suitable for use inINFINITI vehicles.If any undesirable driveability problems such asengine stalling or hard hot starting are experiencedafter using oxygenate-blend fuels, immediatelychange to a non-oxygenate fuel or a fuelwith a low blend of MTBE.Take care not to spill gasoline during refueling.Gasoline containing oxygenates can cause paintdamage.Technical and consumer information 9-3"
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