schmenke

Hi i2i2i2, my experience is based on a couple of recent camping trips where we drove the identical route, under pretty much identical conditions as our previous trips to the same campground when I used 87 octane. The difference was noticeable, particularly on the hills where the truck pulled with less effort and/or maintained the same speed in a higher gear. Pulling away from a standing start seemed to be easier as well. Overall, the truck seemed to have more torque.

schmenke

Yes, this might make a difference.

mhendrickson81

We are leaving on a trip this weekend. Going from Houston, TX to Branson, MO. I'll do a little experiment and run as normal on the way up and then I'll get the good stuff on the way home. I'll let you guys know what I notice when we get back.

i2oadi2unnei2

Crap, now I got another dumb question What happens when you're mixing the two? Don't do it? See it as a regular gas? This question is for you pseudo gas/fuel experts lol.

duck9191

the octane will average to what ever ratio is in the tank.

mhendrickson81

From Sunoco. It deal with race fuels. But the math is still the same.

We often get these two questions:

1. Can I mix fuels?
2. What is the octane when I mix them?

The answer to #1 is easy. Yes, you can mix any of our race fuels. But remember – if your engine needs an unleaded fuel, you don’t want to mix leaded with unleaded. Doing so would make a leaded fuel which could still damage oxygen sensors and catalytic converters.

The answer to #2 requires a little math.

First you need to calculate the percentage of each fuel that will be in the final mixture. Then, use this equation to find your octane:
( [ % Fuel A ] x [ Octane of Fuel A ] ) + ( [ % Fuel B ] x [ Octane of Fuel B ] ) = Octane of Mixture

Here’s an example. Let’s say you mix 3 gallons of 110 with 2 gallons of 100 and you want to know the octane of the resulting 5 gallon mixture.
The percentage of 110 in the mix is 3/5 = 0.60 (60%).
The percentage of the 100 octane fuel in the mix is 2/5 = 0.40 ( 40%).
Plugging the information into the equation:
(0.60 x 110) + (0.40 x 100) = 66 + 40 = 106
So the octane of the resulting mixture is 106.

BlackBoost

To be fair, even a small breeze makes a big difference in mileage when towing a sail so it's hard to go just off of that. Been down to Canyon Campground down by you, over to Drumheller, up to North Buck Lake, west to Carson-Pegasus, all many trips taking the same routes every time, and the mileage is always different each trip. On mild days with no wind to speak of, I can get 11-12.5 MPG, driving the same routes, same speed (cruise on 100) and it's only maybe a slight breeze that's different. The absolute worse I've had is 9.5 MPG during a bad wind storm a few weekends ago.

BlackBoost

It's fine to do it, but that's why when you've changed octane, you should run your tank as low as you can, provided it's not very hot out since the fuel cools the fuel pump. It also takes a couple tanks for the truck to adjust fuel maps. Whenever I've tried testing premium, I've run 3-4 tanks of it to see if there's a difference. I've done this a few times over the year, no difference for me. That's why I just stick to regular.

schmenke

Nothing bad will happen if that's what you're concerned about. The engine knock sensor will automatically signal the ECU to adjust the timing to maximize the compression based on whatever fuel octane (or RON) rating is being injected.

schmenke

Yeah, fair enough. Just my observation. Like I said, I notice the diffence mostly pulling up hills.

And yes, I too notice a big difference in fuel economy during strong headwinds (the fact that my TT is about as aerodynamic as a brick doesn't help). I've seen everything from 19 liters/100 kms to 24, depending on the winds (recently had a nice tail wind eastbound on highway 3 near Pincher Creek and the dash reading was in the 18s at 100kph).