Mixing premuim with regular gas
- Thread starter KevinV
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Gas stations that sell 3 grades of gasoline sill only have 2 underground tanks.
Guess how they do that for the middle grade?
You're correct.
Guess how they do that for the middle grade?
You're correct.
Did you google the Mr internet? I think the molecules are different but it should not make much difference. I have done it with no noticeable impact.
What jack said. "Mid grade" gas is mixed at the pump with a blend of the regular and premium tanks.
Originally Posted By: KevinV
If you mix 87 octane with 93 octane, gallon for gallon, do you get 89 octane ?
(87+93)/2 = 90
If you mix 87 octane with 93 octane, gallon for gallon, do you get 89 octane ?
(87+93)/2 = 90
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Originally Posted By: Quattro Pete
Originally Posted By: KevinV
If you mix 87 octane with 93 octane, gallon for gallon, do you get 89 octane ?
(87+93)/2 = 90
Quattro They have gas stations in Texas that say 87 89 and 93 octane. I know the 89 and 93 is blended, so not sure why they say 89 when it's really 90. That's where he's getting the 89 number from.
Originally Posted By: KevinV
If you mix 87 octane with 93 octane, gallon for gallon, do you get 89 octane ?
(87+93)/2 = 90
Quattro They have gas stations in Texas that say 87 89 and 93 octane. I know the 89 and 93 is blended, so not sure why they say 89 when it's really 90. That's where he's getting the 89 number from.
Originally Posted By: motor_oil_madman
Quattro They have gas stations in Texas that say 87 89 and 93 octane. I know the 89 and 93 is blended, so not sure why they say 89 when it's really 90. That's where he's getting the 89 number from.
How do you know the pump blends it in a 1:1 ratio? Besides, its going to depend on the highest octane (whether 91 or 93).
Also the 93 is not blended.
Quattro They have gas stations in Texas that say 87 89 and 93 octane. I know the 89 and 93 is blended, so not sure why they say 89 when it's really 90. That's where he's getting the 89 number from.
How do you know the pump blends it in a 1:1 ratio? Besides, its going to depend on the highest octane (whether 91 or 93).
Also the 93 is not blended.
Originally Posted By: motor_oil_madman
Originally Posted By: Quattro Pete
Originally Posted By: KevinV
If you mix 87 octane with 93 octane, gallon for gallon, do you get 89 octane ?
(87+93)/2 = 90
Quattro They have gas stations in Texas that say 87 89 and 93 octane. I know the 89 and 93 is blended, so not sure why they say 89 when it's really 90. That's where he's getting the 89 number from.
As was posted earlier, the pump does not blend at 1:1 ratio to achieve 89. 2:1 ratio should give you 89. 1:2 ratio should give you 91.
The OP asked about 1:1 ratio in the sentence I quoted, so that's how I answered.
Originally Posted By: Quattro Pete
Originally Posted By: KevinV
If you mix 87 octane with 93 octane, gallon for gallon, do you get 89 octane ?
(87+93)/2 = 90
Quattro They have gas stations in Texas that say 87 89 and 93 octane. I know the 89 and 93 is blended, so not sure why they say 89 when it's really 90. That's where he's getting the 89 number from.
As was posted earlier, the pump does not blend at 1:1 ratio to achieve 89. 2:1 ratio should give you 89. 1:2 ratio should give you 91.
The OP asked about 1:1 ratio in the sentence I quoted, so that's how I answered.
Correct, if you want mid-grade, blending 50/50 87 & 93 is the way to go, giving you 90. Taking the price of the 3 grades into consideration, of course.
"mid grade" is not a spec, to be precise they spec an octane rating. But they have to write it out as Premium or Regular because it's found that users are idiots.
Even within the US, often dependent on elevation, the octanes are different for midgrade/premium. So say your car specs 89 "regular", but you're up in denver where 89 is considered midgrade or premium, and you're planning on going to sea level, you might want to get the midgrade.
Even within the US, often dependent on elevation, the octanes are different for midgrade/premium. So say your car specs 89 "regular", but you're up in denver where 89 is considered midgrade or premium, and you're planning on going to sea level, you might want to get the midgrade.
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Originally Posted By: dmdx86
Are there cars that actually spec the mid grade octane? Always thought it was just premium, if your car called for it.
Generally it is for cars that were designed to run on 87, but have too much carbon build-up and ping on 87.
Are there cars that actually spec the mid grade octane? Always thought it was just premium, if your car called for it.
Generally it is for cars that were designed to run on 87, but have too much carbon build-up and ping on 87.
i don't see a problem but
what are you trying to accomplish?
what does your car manual say?
what are you trying to accomplish?
what does your car manual say?
Originally Posted By: dmdx86
Are there cars that actually spec the mid grade octane? Always thought it was just premium, if your car called for it.
My old BMW does (89 or higher), but that's the only one I've ever seen that does.
Are there cars that actually spec the mid grade octane? Always thought it was just premium, if your car called for it.
My old BMW does (89 or higher), but that's the only one I've ever seen that does.
Originally Posted By: kschachn
Originally Posted By: dmdx86
Are there cars that actually spec the mid grade octane? Always thought it was just premium, if your car called for it.
My old BMW does (89 or higher), but that's the only one I've ever seen that does.
I don't recall off the top of my head, but I know there are some cars that say for best performance use 89 oct. or above. I think the Chrysler 300 with the 3.5 V6 was one. On my 90 DeVille premium was specified, but worked perfectly on 87. It had no knock sensor, so I guess they just wanted to be safe (or just figured "hey, it's a caddy, put premium as recommended
).
Originally Posted By: dmdx86
Are there cars that actually spec the mid grade octane? Always thought it was just premium, if your car called for it.
My old BMW does (89 or higher), but that's the only one I've ever seen that does.
I don't recall off the top of my head, but I know there are some cars that say for best performance use 89 oct. or above. I think the Chrysler 300 with the 3.5 V6 was one. On my 90 DeVille premium was specified, but worked perfectly on 87. It had no knock sensor, so I guess they just wanted to be safe (or just figured "hey, it's a caddy, put premium as recommended
I have never seen a blending pump outside of Iowa and those were only for ethanol. If there are three grades there are three tanks.
All gas stations here use blending pumps. It's always been that way AFAIK.
We just got back from a road trip that was a total of 1600 over the past four days. Before we left we had only put like 500 miles on this 2006 Ford Five Hundred with the 3.0L V6 with the Aisin Warner 6 speed auto. MPG in this small engine did not vary between 87 with ethanol or Shell Premium Ethanol FREE 91. We hit about 26 MPG come and the weather was a winter mix running 70-75 MPH running new like Arctic Claw Winter TXI M&S tires that do roar some so I expect at 75 MPH we take a hit on MPG. They one the FWD are Awesome for control both to start and to stop in snow. The roar is not bad but I hope to pick up another set of wheels for an all season set by mid April.
Now the 1992 TBI 454 in the old motorhome makes more power and gets better MPG on ethanol free premium gas vs 87 with ethanol 10%.
As noted already some engines prefer more octane and it is a waste in other engines.
Now the 1992 TBI 454 in the old motorhome makes more power and gets better MPG on ethanol free premium gas vs 87 with ethanol 10%.
As noted already some engines prefer more octane and it is a waste in other engines.
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