85 Octane in Colorado? Toyota says yes. What do you say?

I use 91... I know people are going to hate on me for it but I swear I read somewhere that the same engine in a Lexus calls for premium and that the ecu can retune itself to get a tiny bit more power with the higher grade. No idea if it's true but I don't really care, it seems to run a little better and I'd rather have cleaner fuel in the car.

what is this based on? im not hating, im asking, because im not sure that is true.
 
I use 91... I know people are going to hate on me for it but I swear I read somewhere that the same engine in a Lexus calls for premium and that the ecu can retune itself to get a tiny bit more power with the higher grade. No idea if it's true but I don't really care, it seems to run a little better and I'd rather have cleaner fuel in the car.

I just want to clarify a misconception. Octane rating DOES NOT necessarily mean cleaner fuel.

While some company's DO add more detergents to their higher octane fuels, not all do.

Carry on.
 
The EPA needs to ditch the ethanol mandate.

Tell that to Iowa...

Considering Ethanol is a net-loss energy source and uses lord knows how many gallons of fresh water per gallon of fuel to produce as well, ethanol should be banned if there was any sense at all in energy policy. Growing food for net-loss energy sources, nice 1st world problem to have. Now that the U.S. is either the second largest oil producer next to Russia, or the largest oil producer on Earth, this makes zero sense other than to subsidize an entire state's false economy and then some. Not to mention the fact that ethanol ruins engines. Brilliant.

Interesting discussion on octane and elevation, thanks.
 
The owner's manual specifies a minimum octane level of 87. Octane is simply a fuel's resistance to knock. If you understand the causes of knock, then that may help you decide what octane level of fuel is right for you. Modern engines have knock sensors and a light knock is best for fuel economy and performance, however, knock sensors are reactive and not proactive.

I have no problem paying for 93. I tried 87 when I first bought my 4R and the engine felt too restrained to me, as though the engine was struggling a little; and this was right before the heat of Summer time. With 93, I am satisfied w/ the engine performance (read: I was not expecting fuel economy gains w/ 93). However, I might try 89 in the cold Winter months.
 
I do. I drive back and forth between Monument & Denver.

I will say there is a notable improvement when I do splurge and drop a tank of 91. I often go back in my head to the supercharger thread when one of the original testers mentioned that during his baseline testing before the install the amount of timing that he was seeing pulled on 87 Octane.

If I wasn't running 70-80 miles or more a day, I'd definitely run 91 octane full time.

The benefits of having a Costco membership. 91-octane gas for 87 prices at most other places. That along with a hot dog and soda for $1.50 :D :D :D
 
I use the cheapest gas I can get, so I've also used 85 when hanging around utah and colorado and not a problem.
 
The owner's manual specifies a minimum octane level of 87. Octane is simply a fuel's resistance to knock. If you understand the causes of knock, then that may help you decide what octane level of fuel is right for you. Modern engines have knock sensors and a light knock is best for fuel economy and performance, however, knock sensors are reactive and not proactive.

I have no problem paying for 93. I tried 87 when I first bought my 4R and the engine felt too restrained to me, as though the engine was struggling a little; and this was right before the heat of Summer time. With 93, I am satisfied w/ the engine performance (read: I was not expecting fuel economy gains w/ 93). However, I might try 89 in the cold Winter months.

The owners manual specifies that because most places, that’s the lowest octane you can get. In colorado, it’s lower because of elevation but they wouldn’t make manuals by state because thatd be a lot more difficult to manage. They probably make one and put it in every car regardless of where it is sold. There is no such thing as 93 here so I think the scale is shifted to the left and 85 in Colorado = 87 elsewhere.
 
Use whatever the manufacturer recommends. No higher octane is needed, and running a higher than required octane is just costing you more money. As to the OP's original question, higher elevations require less octane, which is why places like Denver sell lower octane fuel.
 
I use 91... I know people are going to hate on me for it but I swear I read somewhere that the same engine in a Lexus calls for premium and that the ecu can retune itself to get a tiny bit more power with the higher grade. No idea if it's true but I don't really care, it seems to run a little better and I'd rather have cleaner fuel in the car.

Mine definitely runs better with 93 Octane in the Texas summer when the temps are hovering around or above 100. That is for city driving.
 
There is no such thing as 93 here so I think the scale is shifted to the left and 85 in Colorado = 87 elsewhere.

Manufacturers usually specify 87 or 91 for their cars (89 on rare occasion). In my area, we get 87, 89, and 93. It makes you wonder why 93 and not 91. Perhaps in my area, those 2 extra octane points are to accommodate the elevation and hot climate for cars requiring 91. If that is the case, then would it not make sense to apply the same logic for cars requiring a minimum of 87, and use 89?

(Yes, it makes sense to offer 85 in Colorado as there is less oxygen at that elevation and cooler climate. I wouldn't do an interstate trek from that elevation/climate to Amarillo (example) on a tank of 85 and a full load of family and gear in the middle of a Texas Summer)
 
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what is this based on? im not hating, im asking, because im not sure that is true.

I've been informed I'm wrong about that. Someone told me a long time ago that higher octane fuels tended to be cleaner and better for the fuel injectors and I never bothered to check.

So, I guess I learned something new today.
 
Been running 85 since I bought the 4Runner in 2009. No problems noted, no repairs on engine at all. Mixed city and mountain towing a boat over 13K passes, ski trips...no problems. And I still sleep well.
 
It just has to do with the elevation. So at sea level you have 87,89,91 and when your at elevation like in Colorado you have 85,87,91 because there is less oxygen in the air it requires less "octane." So if your running 85 octane running around Denver metro area you'll be fine and if you run into the mountains you'll be fine as well. If you run 85 Octane and drove that tank of gas all the way to the coast you MAY experience engine knocking, bu the chances of that tank of gas lasting that long is slim.

If your constantly running your vehicle at 10,000+ feet in the mountains it would be "better" to run 87 octane in Colorado. Otherwise in Colorado the 85 is equivalent to 87 on the coasts.
 
Been running 85 octane here in Colorado in ALL my Toyotas that call for for regular for 33 years with ZERO issues.

There is the same amount of Oxygen in the air at altitude as at sea level it's just the air is less dense.
 
I've run 85 in Colorado without issue (Leadville if I recall)... it was however only one tank. I refilled with 87 once I made it down to Alamosa.

Side note: I had the best MPG I have ever documented coming from Alamosa down to Santa Fe. Even with 4 adult passengers and a weeks worth of luggage for each of us. 25+.

Same. I filled up last week with 87 in Alamosa and got 24 going down to SF. My previous best was 21. Must be some special gas...
 

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