Gas Octane

I just towed a 3500 lb trailer from Denver to San Francisco. I only used 91 octane for towing. My mpg's were 13.2. 13.2, 18.2, 17.2, 17.3, & 18.3.

The 13.2 mpg's were due to gusts of wind up to 75 mph in northern Colorado and throughout Wyoming. My trailer is low profile so I didn't have too much of a problem. I saw a couple of higher profile trailers get turned over because of the wind.

Once I got past the wind I was averaging 17-18 mpg even through the mountains which is great because I was expecting 15 mpg or so.

My engine was struggling at first because I was using 87 before I started towing. Towing with 91 makes a HUGE difference with power.

 

I have noticed that with 91 I get better mpg when I am doing 75+ on the freeway, with 87 the engine seems to struggle and my mpg drops significantly.

 

So... I have been running 91 octane in my V6 for just over a month now. Just to see if it made any difference.

I have put three tanks of fuel through her, and fuel economy has not changed, enough to really count anyways.

Although I feel the engine is a tad more peppy, it could be my imagination. As chris4x4 said, "On the 1GR-FE, running 91+ octain does in fact make a difference in performance."

I believe it may have some performance benefit, but no fuel economy benefit, so for the extra money, it is not worth it to me to run 91 octane. I will be switching back to 87.

edit: I am back to 87 octane, 91 or 94 had no benefit except possibly being cleaner, and with more additives.

 

A quick google found that Jet-A / Jet 1 fuel have kerosene like properties, but jet fuel is a mixture of many hydrocarbons. It has a lower smoke point than gasoline, and burns slower...


And does lots of other stuff that I don't feel like copying off wikipedia

 

Avgas contains low levels of lead. In fact you most commonly see it listed as 100LL. The "LL" is low lead. Good for engines but not so good for cats. It should not be run in these trucks.

 

I havent read though all of this way to much. I put the cheapest in mine force of habit. but my 2 cents I use to have a BMW which asked for 93 so I went along with it, I was in highschool at the time so when funds got low and it was between gas or beer... beer won. when I put the cheap stuff in the german it would bong down when I punched it off the line or down shifting up hills. it would stop when I put 93 in. But I always see just one tanker filling the tanks.. to each there own I guess...

 

stay thirsty my friends, I used 91 or at least 89 if 91 isnt avail, sometimes do the 87+91 mix, hard to find 93 in Maine

 

I went to 89 from 87 but found no increase in MPG. I guess I will try 91 see what I can get Any help in MPG is worth it

 

Couple things I noticed on this tank of 93 (chevron). I got 423 miles out my tank. I topped it off and ran it till the line was below E. Filled up a total of 21.1 gallons.

 

Here in Colorado, the highest octane they sell is 91 so I use it but if I am in any other States where the highest is 93 then I use it. I have on a few occasions used lower octanes but my truck always runs better with the higher octanes.

 

I switched to 91 and noticed better mpg on my v6 double cab, haven't done the math to see if it's worth it but what I'm doing is filling up at Costco with 91 for almost the same price as 87 on regular stations

 

Generally, you get more miles per dollar with premium from the stats I've compiled. And there is no doubt at all that you get more HP and torque from premium, that's why Lexus recommends premium so their HP and torque stats are increased. I run premium all the time, synthetic oil also. It pays off.

If all you do is commute, never have to accelerate too much, no loads, 85 is ok, but real truck use top grade is the best way to fuel up.

 

I have been trying the same thing. I found a place with 92 ethanol free. I too was thinking it had a little more pep but I figured it was just the new tennis shoe syndrome.

It seems with the scan guage on the freeways the MPG might be a little better but overall I think it is just the same as the 85. I guess I just have a lead foot?

 

It's been said (and ignored) a million times. You won't feel much benefit from the higher octane gas till you use the truck under load. If you are hauling or towing it makes a big difference. If you are just running around town, the power is still on tap but isn't demanded.

 

Short Story:

A number of years ago my Father-N-Law went to the gas station where he would usually fill-up. While there the supplier was filling up the tanks. Being the talkative guy that he is, he starts chatting with the supplier guy. Now, this station would sell the 3 levels of octane(87, 89, 93) and diesel. One thing caught the FNL's attention while chatting. There were only 2 ports for the supplier to fill the tanks. One was white and the other was green.

You guessed it!!!, The station was ripping off people who were purchasing the higher octane gas. When the supplier guy was questioned about this all he could say was that he just fills the tanks available and is not responsible for any of that. Needless to say, today, that same station only has 2 options. 87 octane and diesel.

Lesson learned- Always count the number of ports that are in the ground. There should be a red, white , and blue for gas. and a green for diesel. And, even then, who is say that 87 octane isn't being pumped into all 3 ports? dunno

I personally use only non-ethanol 87 gas for this very reason. I know I'm getting what I'm paying for. It easily out-performs any of the ethanol blends and I get and extra 2+ MPG.

 

It's been suggested (and not believed) a million times. You won't get much better MPG from the higher octane gas till you granny it on the freeway. If you are doing regular driving it makes no difference.

 

445 miles on the last tank of 87 and 10% booze 22.7 MPG last time I towed the camper 3000#+ 15.1 Why would I want to waste money on 91?

 

Downhill? With a Tail-wind? How the hell....

I thought I was doing pretty well...33" tires and a 2.5" lift with a Bestop, and I'm averaging 18mpg in the city! I think the catback and drop in K&N helped a lot. I was averaging 14mpg city before those two additions.

 

Slowing down 10 mph with the trailer was good for 4-5 mpg last years trip to Canada at 70+ maybe around 10 mpg speed really kills the mileage. Not driving the truck like I stole it gives me the road mileage. I live in the boones and it's an hour drive just to get to the interstate so rarely do I get to go more then 60. The truck is bone stock with 35 psi in all 4 tires.

 

Exactly correct. The map for premium for this particular engine makes almost no more horsepower, but 12 additional ft lbs of torque. Not especially useful for tooling around, but helpful for towing. I accept if a guy doesn't need it, but I never understand people's insistence on denying it.