Koz:

I checked the web site you provided for Top Tier Fuels and it seems most the major brands are represented ... except Valero, which is the cheapest in our area. Your advice is to buy gas only from stations on the Top Tier list, right? Would there be any indication on the pump or is the brand all you need to shop for?
Regards,

SaniDel

 

Excellent post! And right on the money. But don't try to tell it to these hammer heads who persist in believing that higher octane is always better and that it always boosts mileage. Old b.s. is very slow to die.

 

My bought-new 2005 RX330's recommended fuel was mid-level (often called "Plus") but the manual said regular was OK if the owner prefers. I ran regular for the last 3 or 4 years I owned that vehicle and never had any problems nor did gas mileage decrease. It had nearly 85,000 miles on it at trade-in and was running great. My new 2013 RX350 calls for regular, period.

 

toyota does likely use different components in their lexus vs toyota engines. i have a hard time believing that its just "tuned" differently.

 

Some time ago there were only a few brands on this list. You will not see any indication at a gas station of them being Top Tier. I only use Top Tier (Shell V-Power). I'm a very aggressive driver and tow often, so I use the higher octane (could get away with the middle grade).

Recommendation - Stay away from vehicles/engines that have (only) direct injection. The fuel is injected directly into the cylinder and does not flow through the intake system, which would be cleaned by the special additives in the fuel. No manufacture has designed a system (direct injection) that will stay clean enough without periodic cleaning. This periodic cleaning can get VERY involved (and expensive).

Koz

 

The term "Tuned" includes different cam profiles and other component differences in the design of the engine. It is not just different mapping of the fuel delivery system.

Koz

 

Have only owned my GX for three weeks. I have a tad less than 1100 miles on it. Today I messed up and put about 1/2 tank full of Plus grade fuel in it. This was 89 octane. The half a tank that was in there was 93 octane. I know it retards the timing. My question is once I get this out of the tank and refill with 93 octane will the timing return to normal? I will only be driving around home until I get the gas out of it - not over mountains or anything, of course all of WV is hilly - that is why we are called the Mountain State. Will not be towing or anything like that. I hope I did not screw up too badly!

 

No harm, it won't hurt anything and will go back to full power once you burn it out. I had to ask my dealer to fill mine with premium, they usually fill with mid grade.

 

That's a load off my mind. I went to a station and their pumps were messed up - brand new install of pumps and tanks. Used to be another brand- now Shell. Anyway you had to pre-pay cash or debit inside as the pumps would not scan. I went in and she ran my debit card. When I went back out I hit premium which was 3.499 and pumped my $40.00 worth. When I got my receipt and went to put the numbers into my GasCubby app on my phone it said 3.399 so I went in and questioned it. The lady said "Oh, we have not gotten the premium in the new tanks yet so it just gives you plus on both buttons! " I was majorly ticked off but what could I do - the gas was already in the tank. I told her I was going to call corporate but she just went back to her peanuts and National Enquirer. I am going to contact Shell but it will do no good. Thanks for letting me know I did no serious damage.

 

You're welcome!

 

You can run regular in it (87) with no issue. The computer will compensate for the lower octane. My company has had LS460's since 2003, 2 cars with 3 year leases with 25k a year, never once had an issue with running 87 octane in them. So 6 of them and no issues, I'd say you're safe.

 

Not to beat a dead horse (since, as others said, you are absolutely fine and would be even with 87), but on a side note...

If you had about half-a-tank with 93 and filled up with 89, the average (so to speak) octane in your tank is 91 at the moment, and Lexus' premium gas recommendation is actually 91, not 93, so you are better than fine. Enjoy your new GX; I hear it's fun to drive on the mountains

 

Find the tallest building and jump off, you have dishonored your Japanese Make and offended the forum.

Seriously though, you're fine.It will be burnt through in no time and you will not even notice it.

You do understand though, this will go on your "Permanent Record!"

Randy B

 

I know all about "It goes on your permanent record!" I was a teacher and coach for 35 years. That was the ultimate threat. Not to worry though, we have no tall buildings in WV! The town where I taught just got it's second stop light a few years ago.

 

I've run lower grade fuel than recommended in my cars sometimes and the only thing I ever noticed was a slight decrease in pep during acceleration and sometimes reduced fuel economy. The car's computer will adjust accordingly and things always went back to normal after the next full tank of 91 or 93 octane.