Octane ?

Hey guys, quick question. The manual states we need 87 Octane in the truck. In every state I've been in that is the low grade, but here in CO, that is the mid grade. So two questions really, can we get away with 85? And why 85 in CO?

I also want to mention that part of my hesitation to use mid grade fuel is based off of a fact I learned from my uncle, who sells fuel pumps for a living. He explained that mid grade is not regulated, and it is a simple mixture at the pump of high and low grades. The mixtures are very often off, so it may be closer to low grade then it is to high grade most of the time. I don't want to pay the difference if I my just be getting 86 to begin with.

Thoughts?

 

I run 87 in mine, never knew about the mixture at the pump deal.

 

I run 89

 

So, I did some research and found this:
"
What is 85 octane, and is it safe to use in my vehicle?
The sale of 85 octane fuel was originally allowed in high-elevation regions—where the barometric pressure is lower—because it was cheaper and because most carbureted engines tolerated it fairly well. This is not true for modern gasoline engines. So, unless you have an older vehicle with a carbureted engine, you should use the manufacturer-recommended fuel for your vehicle, even where 85 octane fuel is available.
"
https://www.fueleconomy.gov/feg/octane.shtml#85

 

You are correct, mid grade is a mixture of high and low. It's controlled by the controller software that provides a 50/50 mixture. I'm in the biz and it's a close mix. Not enough variance to make a difference

 

What does 91 do to our engines?

 

when that happens I'll have another motorcycle to commute on ;-)

 

Nothing just burns a hole in your wallet...... I use 87 pure dino most of the time.

 

Nothing! Been running 92 octane for the last year. There is definitely a difference. The engine runs smoother, quieter, and quicker throttle response. Is it worth it? No, but it's hard going back to something less superior.

 

I use 87 up to 93 just depends. Never used 85.

 

Ditto X100000000^^^^^^^^^^^^^

 

Our trucks are factory tuned to perform best with 87. There really is nothing super about premium grade gas. It all depends what your tune is.

 

I know around here some places carry ethanol free in 91 octane, so it is only on premium. So if you ran premium that was ethanol free you might notice it run better than regular, and get better MPG.

 

Then there is that Tow/Haul mode problem........

 

It’s a good problem to have

 

I drive like a grandpa because my one income cannot support a family and my lead foot

 

I don't see the "problem," lol the wife does!

 

I run 91 but I’m tuned. It runs real nice! To compensate I have a Costco card so I can get their Arco prices with Chevron gas LOL so I’m pretty much paying 87 prices.

 

Wait, if you have a costco card you can get a discount at Chevron? Never heard of that, I need to check this out

 

Here in FL the three octanes are 87, 89, and 93. I run 87 in the Tundra because that's what the manual specifies. However, I run 89 in the Mercury I have because it sits for long periods of time and I've read gas loses some of its octane if it sits over time. Plus I've also heard that the Ford 4.6 develops a knock eventually if 87 octane is run through the life of the engine. Apparently the 89 helps with that.

Any reason I should be using the 89 on the Tundra? Is it better for performance or throttle response? Does it burn cleaner? Just figured I'd go by the manual but now you've got me wondering.

 

85 is fine in Colorado and wherever they sell it, parts of Utah etc. They sell 85 where the elevation is higher, less dense air, less likelyhood of detonation. Just don't fill your 38 gallon tank and drive to Phoenix and then promptly beat it to hell in lower elevation heat, your ecu will pull timing and you won't be happy with the performance. Unless you are towing or want every last once of hp run the least expensive fuel.
A Land Cruiser is tested on 87 and makes 381hp, a LX570 is tested on premium and is rated at 383hp, so you will gain 2hp running premium fuel

 

Yep, one tank of highest octane one lowest. Mid grade, 91 or 89 around here, mixed as you pump.

 

If y'all don't know, running 87 on a stock motor actually pulls 10-13 degrees of timing, 6-8 on 89, and 0-2 degrees on 93. Food for thought. This is on stock tuning. The data logs are on Facebook from DAP tuning. The 4.6 and 5.7 hate 87, run the best on 93. Don't believe me, go do your on research Facebook with the guy who actually data logs the knock sensors. 91 or 93 is the best on these trucks under load. Anyone who disagrees with me, well you can; but you're wrong.

 

I did try a tank of 93 on my Taco pulling 5000lb boat from LaFayette to Dallas. Same conditions. 70-75 mph on IH and light winds. Measured MPGs were +1 on about 15 gallons of gas. So higher octane may provide better MPGs under heavy load. Tried same in Tundra over shorter trip but strong headwind killed the experiment. Got my worst MPGs ever towing boat in to a 25 mph head wind. Pic is rig in Alexandria.

 

I use 91, with DAP tune

 

No I’m saying because Costco is top-tier and I would say it’s probably the equivalent to Chevron. At least that’s what the guy told me LOL But we get it at Arco prices. They said they keep track of what all the gas stations are selling their fuel for in the area and try to be cheaper than all of them even Arco.