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I know the car already has knock sensors to retard the timing, but is it a good idea to buy an IS300 that had 87 octane gas filled its whole life? Will I see any engine failure in the future? What about if the owner filled their car with 87 octane gas "from time to time"?

Bonus question: Will it matter if the owner only used conventional oil but changed it every 5,000 to 7,500 miles?
 

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Oil is fine. The old days of not switching or blending oil. Does not matter. Fully compatible with each other. As for the octane. It is is own fault if he did not take advantage of more MPG with correct octane. As for the future. There is no way to know. If the car has been maintained well and is in good shape. It is unlikely to have too many issues.
 

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Id be more worried about the dino juice left in for 7000 miles. Id bet the carbon build up is terrible. The knock sensors will keep the motor safe. Id look for a different car. I found that if the owner keeps the interior super clean, they also did regular maintenance. And visa versa.
 

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Are you saying there is an IS300 that is currently for sale that you know the previous owner has regularly put in 87, or is this theoretical as if you find one under these conditions?

If it's one you've found that you're sure has had a decent amount, or even up to 100% of its fuel from 87, I would love to know the mileage of the engine.

I've read our owners manual, and it states that it is ok to have 87 in for shorter periods of time, as it pulls timing as far as it can, but doesn't say anything about ALL the time.

As for the oil, as far as I know, conventional doesn't have the same protective additives that a full synthetic blend does, although just having the oil changed period is better than never at all!
 

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Id be more worried about the dino juice left in for 7000 miles. Id bet the carbon build up is terrible. The knock sensors will keep the motor safe. Id look for a different car. I found that if the owner keeps the interior super clean, they also did regular maintenance. And visa versa.
Im agreeing with that statement, From my experience (I've been in the automotive industry for the past 19 years) The cleaner and well kept interior is, the maintenance records are up to date. Thats been the case with Drifthanie too. She'd belonged to an mechanic at Lexus at Tony's Graham in Ontario, She's been loved troughout all the time he got her. Still have Original Documentation from the day it was brand new!!!
 

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I've run 87 for ~220k miles. 0 Engine issues

As others have said, I'd be more concerned about the oil intervals
 

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I've run 87 for ~220k miles. 0 Engine issues
Woah, that seems so risky. I'm also extremely skeptical since it calls for premium and the higher compression doesn't help your case either. I'd love to build a scrap 2J just to confirm this. I would be so worried in the summer as temps rise.
 

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My car has been grannied and cherrish all it's life by the previous owner. I'm not hard on cars (rarely hitting rev limiter, let the thing warm before abusing her, Always using Dealers Oils, Wich in fact is Mobil1) but I liked Spirited driving and burning tires. When I got my car it was unresponsive despite the fact that the Gas Pedal Mod was done! The car was amazing when being driving smooth and feels slugish when the pedal was floored. So after tons of reading and Learning about how the Stock ECU works and learn. I've also changed the Spark plugs for a new set of OEM iridiums. Then I took time to drive the car and let him learn my driving habits and about a few hundreds kilometers Everything was perfect. No more unresponsiveness or any kind of pinging noise, especially when I was taking off from a stop (the throttle blip that I give when I depress clutch)

That being said, Ours ECU and VVTI work great! the 2jz being a 2jz! I'm pretty sure that with a few runs of pressurised Injector cleaner, a full tank of 91 or 94 octane gas if available in your area. Disconnecting the battery for a few minutes then connecting it back. So when you'll start and drive the car it will relearn. You can drive it smoothly for a few days to let the ECU play with VVTI and bring things where it should be. Then Drive your car hard so it will learn an agressive timing also for when you want to have fun with the Traction Control off
 

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Woah, that seems so risky. I'm also extremely skeptical since it calls for premium and the higher compression doesn't help your case either. I'd love to build a scrap 2J just to confirm this. I would be so worried in the summer as temps rise.
Maybe it is :grin:

While I'm not necessarily suggesting it, I'm stating I have not suffered any ill-effects in that many miles. No pinging/detonation problems ever.

I can't vouch for any internal cleanliness differences though, as that is hard to guess. The car sees the redline several times on every drive (and has for all these miles). Maybe that helps clean her out :wink: haha
 

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Maybe it is :grin:

While I'm not necessarily suggesting it, I'm stating I have not suffered any ill-effects in that many miles. No pinging/detonation problems ever.
Interesting, I was logging some of the ECU data the other day and noticed that the car advances timing pretty far, up to 32°. So that seems to give us a decent amount of wiggle room when it detects lower octane fuel. The savings per year is around $400-500 per 15k mi, about a years worth of driving on average

I'll have to give it a go for a little and see where the timing goes, i'm not sure if anyone has posted any info on this.
 

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Discussion Starter #13
My car has been grannied and cherrish all it's life by the previous owner. I'm not hard on cars (rarely hitting rev limiter, let the thing warm before abusing her, Always using Dealers Oils, Wich in fact is Mobil1) but I liked Spirited driving and burning tires. When I got my car it was unresponsive despite the fact that the Gas Pedal Mod was done!
What's the gas pedal mod?
 

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What's the gas pedal mod?
under the dashboard where the gas pedal mechanism meets the throttle cable there is a spring creating sort of damping for "comfort" and absorbs some engine vibrations. pretty effective but this is creating some sort of lag due to spring compression. RC shock tower spacer or a zip tie do the trick
 
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