91 Octane Requirement (1 Viewer)

[APIOQM]

According to the official specs posted today, the LC250 is rated with 91 octane fuel. I’m wondering if the recommendations in the user manual can differ, and whether or not using regular fuel would have warranty implications. There is a pretty big difference between the two fuels in terms of cost of ownership, it is the equivalent of 20 MPG instead of the rated 23 MPG.

 

[LCQ]

The user manual is available on Toyota's site.

https://assets.sia.toyota.com/publications/en/om-s/OM60U35U/pdf/OM60U35U.pdf

"You must only use unleaded gasoline. Select premium unleaded gasoline with an octane rating of 91 (Research Octane Number 96) or higher required for optimum engine performance and fuel economy. At minimum, the gasoline you use should meet the specifications of ASTM D4814 in the U.S.A.."

"If you use gasohol in your vehicle, be sure that it has an octane rating no lower than 91."

"Using unleaded gasoline with an octane number or rating lower than the level previously stated may cause persistent heavy knocking. At worst, this may lead to engine damage and will void the vehicle warranty."

 

[APIOQM]

Thanks! That’s interesting. The language differs slightly from the GX550. Excerpts for ref:

GX:

LC:

I wonder if most people will be using regular fuel and I’m curious to see what sort of fuel economy people can get with regular. Hopefully the EPA ratings are conservative.

Can’t quite wrap my head around why Toyota recommends 87 octane in the Tacoma and Grand Highlander.

 

[LCQ]

Thanks! That’s interesting. The language differs slightly from the GX550. Excerpts for ref:

GX:

View attachment 3572831

LC:

View attachment 3572832

I wonder if most people will be using regular fuel and I’m curious to see what sort of fuel economy people can get with regular. Hopefully the EPA ratings are conservative.

Can’t quite wrap my head around why Toyota recommends 87 octane in the Tacoma and Grand Highlander.

Yeah, wish I had a better understanding of octane between performance ratings vs engine damage. Seems as clear as mud. Gets even muddier at high elevations with 85 and 86 being the norm.

 

[Phillyd2]

Is it the turbos that require the higher octane? I mean, it's a four banger.

 

[Rednexus]

Ouch, around here 91 octane often has a 50-70 cent price increase over 87. For a turbo engine it's normally based around resistance to detonation at the design boost levels. It's not a good idea to run 87 in most turbo engines that are designed/tuned for 91. Presumably the ECU will detect this and limit boost/ignition timing to avoid damaging the engine, but that will likely result in reduced power/MPG, and the warranty issue shown in the manual.

Honestly that's a pretty big detraction for a LC250 as it might erase a good portion of the fuel savings for the turbo/hybrid setup, as well as some of the overall benefits of a more complex system compared to the outgoing GX460. Ford has designed their ecoboost engines to generally run on 87 with some pretty crazy power output...presumably they aren't going to last as long as the Toyota engine but still (it can be done). Also if you're touring around in some remote area, who knows how long that tank of 91 octane you purchased has been sitting around.

All reasons I have an 87 octane tune on my N/A GX.

 

[Jetboy]

That's super odd to require 91 when the Tacoma is 87. There's a 30 minute video where the head engineer of the engine team talks about how they re-designed the T24A for the trucks with 70% new parts to run on 87 and have a 30% longer service life.

Is the LC engine different from the Tacoma?

 

[APIOQM]

I had a thought that maybe Toyota went with 91 in the LC to increase engine longevity, but I don’t know if higher octane fuel actually contributes to that. I’m assuming the Tacoma and 4Runner i-FORCE Max will use regular fuel, but just a guess.

 

[turbo8]

Strange how the 22+Tundra\Sequoia require 87, and the GX550 requires 91, but makes less power.

 

[OSS]

So mpg is higher but octane requirement went up = no money savings at the gas pump.

 

[Banandalorian]

So mpg is higher but octane requirement went up = no money savings at the gas pump.

Likely the top priority of anyone buying a $70-90,000 luxury SUV that is rated at 18mpg combined

 

[APIOQM]

So mpg is higher but octane requirement went up = no money savings at the gas pump.

Over the non-hybrid 2.4T, yes, marginal savings if any. Savings over the old V6s will be significant, and obviously a lot more power. I’m still a bit disappointed considering I started off hoping for 27 MPG on 87 lol.

 

[M1911]

Likely the top priority of anyone buying a $70-90,000 luxury SUV that is rated at 18mpg combined

It's not a top priority for me, but it is a disappointment. One of the things that I don't like about my 200 is that I average 14.5 mpg. Yes, I can afford it but I would still rather spend that money on something other than gas.

 

[2021 LC200]

I did not know this. Makes the 250 I-4 turbo motor a further joke compared to the V6 in the Toyota Prado and 4Runner or the V8 in the 200. Shocking what Toyota is doing in the US.

 

[stridertexas]

A gas station near me has 87 regular and then a 100% unleaded/no ethanol “90” as well.

So no mid grade or premium…

Been wondering if the no ethanol “90” could be the same as 91 or 93 premium with ethanol…

Anyone out there smart enough to know? I can’t find the answer on Mr. Google.

 

[Rednexus]

It's usually state specific. Here in MO all 87 is mandated to have 10% ethanol. I think our 89 is also 10% ethanol, which usually drives up the octane rating. Perhaps the 90 octane rating is the lowest your state is able to offer without mandatory ethanol. I've never personally seen 91 or 93 octane with ethanol in it - most states around here don't seem to require ethanol for anything above 89 octane, and the refiners don't seem to add the ethanol unless the state makes them do it.

FWIW, I do run 10% ethanol 87 in my GX (runs good with an 87 octane tune on it). In my small engines that sit around a lot, I only run no-ethanol 91 octane. Ethanol is hydrophilic and will turn mildly corrosive if it sits around too long. It is famous for destroying the fuel systems on small engines when it sits in the carb bowl for months and corrodes things. I have no issues on any of my small engines running 91 and fuel stabilizer, and they'll start right up after sitting all winter.

I'd run zero-ethanol fuel in my GX if it didn't' cost $0.50+ more a gallon.

 

[Cablebandit]

90 is 90, 91 is 91

 

[shane0mack]

90 is 90, 91 is 91

This guy did the math

 

[Phillyd2]

We use lots of ethanol free gas throughout the year for everything from boats to tractors and chainsaws but not in vehicles because they just don't sit around unused long enough. There's no shortage of information on its many benefits but the bottom line is that it's usually not worth the extra cost in anything that is used regularly.

 

[stridertexas]

Gracias for chiming in. I’ve only heard about how 90 0% ethanol is not a good replacement for high horsepower motors like Vettes or Porsches. Couldn’t find anything about “regular motors”.