New 2019 ... initially 13-odd in the City and could not get over 15 MPG under any condition. I thought trading in my GX470 was a huge mistake. After 4,000-odd miles ... Highway = 19.5 MPG with City in the 14-15 range.

 

FWIW, we just returned from a trip to FL. GX was loaded with 4 occupants and luggage. 900 miles each way with AC on entire time. 2,200 total miles. I alternated between Premium and Regular and noticed no difference in fuel economy.

 

So one of the reasons I went with the GX over the Toyota Sequoia I was initially considering was for the slightly better gas mileage. At first I was elated that my 2014 GX seemed to be getting about 17 mpg average, but I wasn't really paying attention to the "after refuel" metric, which later on I noticed was an abysmal 12.x mpg. The 17 mpg average was likely still factoring in the 700 mile drive home on the interstate from the day I bought it. So I decided to do an experiment, reset everything that I could, and kept the driver information display on the "Current" mpg option for at least a week. Pretty much all of my typical driving is in town, with lots of traffic lights, stop signs, and traffic in general. While keeping an eye on the current fuel economy status, I modified my behavior a bit to see how good I could get it to be. This meant coasting as much as possible once up to speed and not gunning it just for the hell of it. After just over a week, I re-checked both average economy and after refuel options they were both 15+ mpg. Satisfied that the GX was capable of obtaining gas mileage as advertised, I decided to conclude the experiment.

Now, I've noticed I seem to have acquired some muscle memory from the week-long experiment with regard to throttle modulation, i.e., I'm much easier on it and backing off more than before, so hopefully my average mpg will stay higher than before (it should be noted I was gunning now and then those first couple of weeks just as a matter of feeling out the new ride's capabilities...).

 

My 2019 owners manual calls for 91 octane gas that is TOP TIER rated. Neither of these (2) requirements are available in gasoline stations conveniently close to where I live. What do most owners use to keep the GX running as it should without gas containing the proper additives to keep the engine/valves deposits in check and eliminate engine knock?

 

My 2019 GX owners manual calls for 91 octane gas that is TOP TIER rated. Neither of these (2) requirements are available in gasoline stations conveniently close to where I live. What do most owners use to keep the GX running as it should without gas containing the proper additives to keep the engine/valves deposits in check and eliminate engine knock?

 

Good question. I use 93 but also keep a bottle of octane booster in the event I ever need to fill up with anything lower than 91. I also run Lucas fuel.system cleaner with a tank every 5k miles...

 

at one time someone did a big writeup on the octane requirement. from what i remember they said it was something to do with areas with less than optimal fuel so the higher octane was required.
i usually use the cheapest which is usually 87 or 89. havent had any knock issues. also havent done any mpg studies.

 

I use any 'premium' gas available, Costco, Safeway, Fred Meyers. rarely use so called 'Top Tier' - Chevron or Shell.
Never an issue

 

COSTCO is Top Tier.

 

Really? And how much does that "octane boost" really boost your octane.

Most premium consumer octane boosters claim a 4 or 5 point point increase. What they don't tell you is that there are 10 points in 1 octane number, so that bottle of octane boost will "improve" your octane rating from 87 to 87.5

Here you go

 

Oh, and the owner's manual does not "call for" Top Tier, it recommends it.

 

Be careful with OCTANE BOOSTERS if they contain MMT. That stuff isn't good for the fuel systems in modern street legal cars.

 

Thanks gents. I've never had to use it luckily... just carry it with us on remote road trips... west Texas and eastern new Mexico is sketchy for quality gas but with good planning we've been able to avoid it.

 

Don't forget that as altitude increases, the need for higher octane decreases. When I was in Colorado Springs, my 335 (usually requiring 91, but ran OK on 87 unless I was heavy on the pedal) ran quite happily on 85 - even going up Pike's Peak. The GX will be quite happy on whatever the "regular" gas grade is wherever you are in the US.

Octane boosters rely on fancy marketing to obscure the fact that they do very little.

 

I have done long runs on the interstate with regular and premium. I manually calculated MPG and I can not tell a difference. I have done the same in the city with the same inconclusive answer. I have been putting regular (87-89 octane) in my car and I am about to roll over 100K without ANY issues. I also tow a wakeboard boat weekly through the summer and can’t fee a power difference.

I had the same questions with my previous GX470. I used regular gas and it is still running strong with 220K on the odometer.