Who's the first to put regular octane gas on their GX550?

[spiderjoe]

With debates on oil change intervals elsewhere, here is another pointless one, who has ventured into using regular 87 octane gasoline on their GX550? Keep it friendly please

 

[Martyt]

I inadvertently put in 1/2 tank— no issues

 

[ilumo]

Zero chance of that for me. One of those pennywise pound foolish things in my opinion. Sure if you just drive around without using the turbo. But once you hammer on it, pre-detonation could be real and mess up the engine.

 

[FJMainiac]

That's all I use. I had a Landcruiser 100 that called for high octane, and I only used regular. At 250,000 miles rust did in the body, and a sold/gave it to someone in TX who used the engine and drivetrain for a rebuild.

 

[Nuke]

Zero chance of that for me. One of those pennywise pound foolish things in my opinion. Sure if you just drive around without using the turbo. But once you hammer on it, pre-detonation could be real and mess up the engine.

Modern engines typically employ knock sensors to eliminate pre-detonation. Not the case?

 

[ilumo]

Modern engines typically employ knock sensors to eliminate pre-detonation. Not the case?

I view that as an insurance policy. And I don’t want to be using that unnecessarily all the time.
That said I might be an outlier in this group because I use this car only on the weekends and I’ll likely put less than 5000 miles a year on it so my gas costs are negligible versus those using it as a daily driver.

 

[Martyt]

I always use 91 except for the accidental 1/2 tank of 87 I added when I first bought my GX.

 

[Nuke]

I view that as an insurance policy. And I don’t want to be using that unnecessarily all the time.
That said I might be an outlier in this group because I use this car only on the weekends and I’ll likely put less than 5000 miles a year on it so my gas costs are negligible versus those using it as a daily driver.

Good point. Retired, we only do about 4K miles/year. I suppose it grinds on me that a modern engine allegedly cannot accommodate various octane values, albeit reducing the performance a tad.

 

[killy]

Good point. Retired, we only do about 4K miles/year. I suppose it grinds on me that a modern engine allegedly cannot accommodate various octane values, albeit reducing the performance a tad.

No one said it can’t accommodate. It absolutely can. However every trade off has a price.

The engine was designed to use high octane gas, operating outside of its design parameters will result in unoptimal performance. That might be excess wear and tear, higher fuel usage, lower performance, rough running, or some combination of all of the above.

If you are stuck in the middle of nowhere and all you have available is 87? Use that and don’t lose sleep over it. if you are in the middle of the city then use what the engine asks for.

You could also try using the wrong oil in the car to save a couple bucks? Same trad3 offs as above, heck it will even still run. Wouldn’t reccomend it long term.

The engineers who designed the car made choices for a reason, unless you have a strong rationale otherwise I reopened taking their recommendations at face value.

 

[Nuke]

I cannot buy off on "excess wear and tear", but yes, some valid points.