What Octane Gasoline For sc430? Premium fuel required? (Merged threads)
11-24-15, 04:28 PM
#136
My understanding is that our cars incorporate knock sensors which alert the ECU to retard timing if detonation is detected. You may run lower octane gasoline, but expect a performance (and possibly gas mileage) hit if you do.
11-24-15, 06:40 PM
#137
Depends on how you drive.
Own a RX350 and SC430, both of which recommend premium. The RX gets regular and the SC gets premium. The RX is my wife's daily driver and the throttle pedal hardly ever touches the mat. The SC is my pleasure cruiser and the throttle pedal gets buried on a regular basis. Costs an extra 5 bucks to fill the SC which happens about once a month. The RX gets gas about twice a month which is 10 bucks that would be wasted otherwise. And there's my 2 cents.
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Last edited by StillLine; 11-24-15 at 06:44 PM.
11-25-15, 07:47 AM
#138
Helogadget is on target. If the knock sensors are working the timing will be adjusted (retarded) to eliminate ping, and performance/mileage will suffer. And under high load/acceleration conditions you may get predetonation because the timing can't be adjusted enough - that's when your engine is telling you to increase the octane. Remember the word 'premium' is a long-time marketing ploy to manipulate you at the gas pump. There isn't anything 'premium' about it (doesn't contain more energy, etc) - it just contains additives to resist detonation better and is required in high-compression engines to avoid detonation by the heat of compression alone. IF you don't get pinging under high load/ high acceleration AND IF you don't detect significant changes in engine efficiency (mileage) then why on earth would you pay the extra $$ for high octane fuel?
11-25-15, 09:25 AM
#139
So lets say the car doesn't adjust "enough" to retard the predetonation (for whatever reason- ie failing knock sensors, etc) indicated by pinging, can engine damage occur? So why risk it? Why risk even minimally damaging the engine? That's truly why I choose to stay with premium. It was recommend for the car, and I can't deal with engine damage on my SC. If there is even a risk of pinging on a hard line pull, which is how I drive, I will pay the little extra for higher grade gasoline vs huge amounts in future engine repair (I'm in medicine, we call it primary prevention.. like getting vaccines to prevent harmful and lifethreating diseases--- another topic for another time :-) ).
11-25-15, 12:27 PM
#140
Pole Position
Went to Costco to fill up the gas tank today. Out of the habit, I hit the 87 button and only realized when the tank almost filled up. So far, I have not notice any differences.
11-25-15, 02:36 PM
#141
Lexus Test Driver
11-25-15, 03:12 PM
#142
11-25-15, 04:34 PM
#144
Lexus Test Driver
No worries Cole, I run 93 in both of my cars...The Lexus and GM Engineers are respected at my house...
12-18-15, 05:28 AM
#145
Some of you have read my post on my smell coming from my car under acceleration.
After a diagnostic done Toyota said everything reads perfect (97k miles) and the mechanic has seen this before and asked me what type of fuel I use. I told him regular and have never had a problem with knocking and that this is my 2nd SC430. He said at 90k plus he thinks there is possibly build up of carbon, varnish etc and since I never drive the car he recommends premium (BP premium gas )
And to use a fuel cleaner called BG 44k ( 1 can for 3-months then 1 more after that) It is the only thing that dealership uses. It makes sense so going to start using premium and see .
Theazz
2003 SC430
After a diagnostic done Toyota said everything reads perfect (97k miles) and the mechanic has seen this before and asked me what type of fuel I use. I told him regular and have never had a problem with knocking and that this is my 2nd SC430. He said at 90k plus he thinks there is possibly build up of carbon, varnish etc and since I never drive the car he recommends premium (BP premium gas )
And to use a fuel cleaner called BG 44k ( 1 can for 3-months then 1 more after that) It is the only thing that dealership uses. It makes sense so going to start using premium and see .
Theazz
2003 SC430
Last edited by theazz; 12-18-15 at 01:22 PM.
12-18-15, 06:34 AM
#146
Lexus Test Driver
I believe the dealer was referring to BG44K, not BM44K
12-18-15, 01:06 PM
#147
Lead Lap
Good to know. Thanks.
12-18-15, 04:26 PM
#149
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As a ASE Master Technician, you should always put premium in your SC . It was designed for that. I would also suggest using Chevron and throw a bottle of techron in a couple times a year to keep the engine clean and the valve. When you use lower octane fuel and cheap gas in these cars, you diminish the life of the engine. These engines are too expensive
12-21-15, 03:14 PM
#150
Have run regular in every vehicle I and my wife have ever owned. This includes 2 V8 Cad's. Been running regular in her '09es since new and in my '04 430 for 5 yrs. Never a sound, but I do watch closely & spend my money elsewhere. Not knocking those that choose premium, its a choice. BTW, I was one of the hard heads that knocked the gas tank insert out in the 70's to run leaded in my Cad......130K mi. when traded.