Mixing Octane

[Quint]

When I tow my boat or snowmobile up north, which is quite frequent, I find that most of the gas stations don’t have 89 octane. Therefore I fill up half of the tank with 87 and half with the 91 (non-oxy) gas in order to make my own blend.

Anyone else have to do this?

 

[OldMarine]

never HAD to do this, but it is perfectly ok to do it, and if you do 50-50, you will in fact get 89 oct. It's what actually takes place in the underground tanks when you pump 89.

 

[Quint]

From what I've heard, it depends. It sounds like most pumps mix the two octanes but I've talked to a few stations where they said that they had a separate tank for the mid-grade. I don't know if that's true but just what I was told.

 

[OldMarine]

From what I've heard, it depends. It sounds like most pumps mix the two octanes but I've talked to a few stations where they said that they had a separate tank for the mid-grade. I don't know if that's true but just what I was told.

maybe some gas stations have a seperate tank to hold 89, probably older mom & pop stations that have not upgraded since Hoover was prez... "There's nothing wrong with mixing premium and regular gas in the same tank. In fact, this is how midgrade gas is formulated at the station. Rather than drawing from a separate storage tank for each octane rating, gas pumps actively mix high-octane fuel with lower-octane fuel to create midgrade gas." Should You Use Premium Gas in Your Car? | Capital One Auto Navigator

 

[Jako]

Blending your own can save some $$$$.

89 Octane Blend

Went to gas up at Wawa in Blakeslee Pa. (route 940 and 115). Something didn't seem to work out with gas prices and did some math. I "blend" 87 and 93 at Costco all the time as that is the only option if I want 89 however Wawa has 89. Octane and prices: 87 octane 3.999 89 octane 4.419 93 octane...

5thgenrams.com

 

[CalvinC]

I like to add E85 to my 91 to get 93!

 

[SD Rebel]

You can mix them for sure, that's how they get mid-grades. I've heard it's done at most stations by blender pumps, but also can be done from the truck, probably as someone mentioned a separate mid-grade tank, they may have to premix from a truck to those station tanks.

My location stations from what I've seen using blender pumps that automatically mix regular & premium.

 

[cskindt]

Yes. My local station has 89 w/ethanol and top tier 87 and 91, both without ethanol. I'll pump 87 and 91 to get something close to 89.
I will never use the ethanol blend if I can avoid it. It's everywhere in IA/NE. In my other vehicles, I always get lower MPG with the ethanol blend.

 

[23RAM]

When I tow my boat or snowmobile up north, which is quite frequent, I find that most of the gas stations don’t have 89 octane. Therefore I fill up half of the tank with 87 and half with the 91 (non-oxy) gas in order to make my own blend.

Anyone else have to do this?

I don't run 89 because I'm at lower altitudes and don't need max power for towing 5k. The RAM runs great on 87. While 89 will give you slightly better fuel mileage and no ethanol helps too, the trade off in price doesn't make it cost effective. You'll spend more for the higher priced fuel than you'll save on better mileage. If you need the added power that 89 offers, then use it. But it's not required. I also only buy from top tier stations with additives to keep my fuel system and engine clean.

As mentioned, most stations only store 87 and 91 octane in tanks, and the pumps simply blend them to get 89. Years ago I spoke with a driver delivering gas to a station one time, and he confirmed they only haul two grades of fuel.

 

[Jako]

Yes. My local station has 89 w/ethanol and top tier 87 and 91, both without ethanol. I'll pump 87 and 91 to get something close to 89.
I will never use the ethanol blend if I can avoid it. It's everywhere in IA/NE. In my other vehicles, I always get lower MPG with the ethanol blend.

Post #6 and #8 - ethanol has higher octane and lower BTUs

 

[HEMIJAKE]

Post #6 and #8 - ethanol has higher octane and lower BTUs

Correct. When I had my mustang, I had it tuned for e30. Ran great on it but mileage was definitely down. It can make good power, just takes more fuel to do so. Personally, I don't worry about using 89 for my truck with as light of loads as I pull, but I understand those that do. There are some useful apps out there for mixing fuel that are helpful too.

 

[Richard320]

I've been on trips in high altitude areas where regular is 85, mid is 87, and premium is 91. I just spend the extra buck or two and go for the premium. Probably doesn't need it, but I feel better about it.

 

[23RAM]

I just spend the extra buck or two and go for the premium. Probably doesn't need it, but I feel better about it.

You might feel better, but your wallet doesn't.

Here in Canada many of the gas stations used "good better best" to describe the fuel grades, which was a lie because putting higher octane fuel in an engine that is tuned for 87, will not benefit anyone except the fuel companies and didn't make your engine run much "better". Using higher octane than recommended generally doesn't make your engine perform any better if it's not tuned for the delayed detonation with higher compression ratios. Due to less ethanol, you might get a slight bump in mpg so you can drive further on a tank, but the cost of the 91 fuel is greater than the savings of increased range in mileage, so you're actually wasting money. After complaints from the public, the companies advertise the fuel grades claiming more fuel additives to clean your engine today, which is still misleading because people think the higher grades clean better but they really don't. It's still just a way to try to sell more expensive fuel that you don't need and not get in trouble with advertising.

Here in Canada 89 and 91 are priced at a higher premium rate than in the US too. As an example, right across the border in NY state a gallon of 87 is $3.79 and 91 is $4.49, that's a 70 cent difference. Here in Canada the same example is 23 cents per liter more which is 87 cents more per gallon (0.23 x 3.78 - a gallon is ~3.78 liters). We also pay a lot more tax at the pump so today's price is 1.63 x 3.78 = $6.16 a gallon, about 37% more. So when visitors from NY come to Ontario, they get to pay 37% more for fuel.
Welcome to Canaduh.

 

[irishwake63]

what ever happened to 87 - 89 - 93 only being 10cents difference between the grades?

 

[23RAM]

what ever happened to 87 - 89 - 93 only being 10cents difference between the grades?

Greed is a powerful motivator.

 

[Quint]

...and what happened to 10cent milk?

 

[23RAM]

...and what happened to 10cent milk?

Ooooo...you're an old fart. How much was bread back then, 5 cents?

 

[Mountain Whiskey]

what ever happened to 87 - 89 - 93 only being 10cents difference between the grades?

Yea, I agree. In Chantilly VA on GasBuddy you can see regular gas (which the truck runs fine on) is $3.65, mid (money thrown out the window at 60mph) is $4.05. This is at 7-11 so it is middle of the road as there are many around. Not bargain Sheetz, not higher priced BP.

Those who say, " Yea, I waste an extra dollar or two on a fill-up" is a farce. It's $0.40/ gallon more for "performance" mid grade gas (I guess the thinking is that a 5.7 in a truck is fast ). I have a 33 gallon tank, consider a fill-up 25 gallons. That's $10. I'll keep that and not worry about the couple 10ths on my 0-60 time in a pickup truck.

 

[6of36]

On my 200 mile trip today, I paid $3.21 at a Sams Club, in Flint, Mi. Even the other stations in the area were $3.60, or more.

 

[Mountain Whiskey]

Ooooo...you're an old fart. How much was bread back then, 5 cents?

5 cents!?! Damn inflation is out of control!