5S-FE fuel?, What fuel to use? Options

[UVZ164]

Hey guys, I'm kinda new here and not sure if this is the right place to post this.

I did a search but couldn't find the specific answers I wanted so I thought i'd ask.
I live in Sydney Aust and the fuels available to us are: E10(10% ethanol) 91 octane, and regular 95 and 98 unleaded.
I recently bought a ST204 ZR which is the equivalent to the American GT. It runs the 5S-FE.
The guy I bought it from told me to steer clear of the E10 as it will ruin the engine. As my wallet isn't that deep I decided to give the cheaper E10 a go.
After about a month and a half of running the E10(i'm assuming the previous owner used 95) i'm beginning to hear a noise almost like tapping when I rev the engine above 3k rpm and just let it decrease naturally. As it never made this noise before, could I be right in assuming that the E10 is doing something and possibly ruining the engine? The owners manual states that 91 octane is as low as you can go but it doesn't say anything about Ethanol.

Thanks in advance,

Reece

[ricochet1490]

E10 burns a little quicker than regular fuel but otherwise it's harmless. The 5S isn't a performance engine, so just use whatever fuel is cheapest and disregard what the previous owner told you. The noise probably isn't anything big, it could be a noise you never noticed before and now that you've heard it, it's easily distinguishable. Or, as Manny said, it could be something very simple.

I would never run "the cheapest gas" in my car, but I guess that's personal preference. I have noticed a difference in performance when it comes to octane. My car likes mid-grade and nothing less. Hess sells "E10" in an 89, which is what I run. Running ****ty fuel and ****ty plugs results in bad cats and premature death of oxygen sensors. Also, it may not be a performance engine, but it is performing higher than it would in a Camry, therefore it should be taken care of better. Your same 5S-FE in a Camry never reaches the RPM's ours does in the Celica because the transmission, unless you smash on the gas, doesn't do it. There is a reason the Camry takes 5W30 oil weight from the factory and the Celica takes 10W30. It has to be protected against thermal breakdown. Yes, our cars are tuned and tweaked by Japan to run at the **** octane we have here, but it doesn't mean that we should accept **** in our cars.

E10 or 10% ethanol will corrode your pump and eat away at the inside of your injectors. It takes time, but it does happen. The best way to avoid damage in the states is to run an ethanol treatment every so often. It protects against the buildup of corrosion and cleans out any possible corrosion that there may be.

Just wait until the government raises the ethanol to 15%.

/TLDR
Do not use the ethanol based gas if you can help it. It will ultimately damage your car and the fuel system.

I also am not buying this for a stinking minute. Other members here have already, and quite eloquently I might add, spoken many of the truths about ethanol. I would like to add that it was in the early 90's that US fuel starting including 10% ethanol. It's a RARE day when I get gas and the sticker doesn't say 10% E. The MYTH about it ruining fuel pumps is ONLY true on pre 1990 vehicles really when the rubber and plastic in the fuel lines was eaten by the ethanol. Now days, and this includes our cars, all of the rubber and plastic in the fuel system could handle 100% E if needed. Whenever I can find it where I live, I put E85 in my car on purpose to about a 50% mixture to reduce my cost at the pump and give the system a little clean. I ran it long enough over the summer i had "trained" my ecu to adjust the A/F to run it at up to 70% E85... and I am obviously NOT a flex fuel vehicle, whose only modification is a sensor to detect presence and percentage of E85 to adjust fuel economy. They don't run anything BUT E85 in many actual racing leagues as well.

Otherwise, to answer your question man.... I run (here 87) the cheapest gas at the pump. I've owned the car for 48,000 miles and I've never noticed a problem, and that includes the "chain sound", or pre-ignition. And trust me, I've driven it HARD at times, never a problem clear to redline. Run the cheap gas, never look back. But do keep an eye on it and check the plugs for damage. In a car of this age however, it could be ANY number of things.... Trust in the 5s, its a work-horse. I call mine Ole' Ironside because of it's indestructibility haha.
Good Luck