mechtech2 said:
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Mid-Grade Gas
- Thread starter sparky123
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I always use the regular but recently I had to get mid grade because there was a "out of order" bag over the regular nozzle.
Don't know if it was a bad load or what, but my Toyota did not like it. It idled rough, felt like I was towing a car, and my mpg went down.
I posted about it,some say if using mid grade, to use the stations that have 1 nozzle for all grades that the chance of the system mixing the low & high (2-tanks) is better than having 3 nozzles (1 for each grade). Where the separate mid grade tank may be the least used hence better chance of older gas.
Don't know if it was a bad load or what, but my Toyota did not like it. It idled rough, felt like I was towing a car, and my mpg went down.
I posted about it,some say if using mid grade, to use the stations that have 1 nozzle for all grades that the chance of the system mixing the low & high (2-tanks) is better than having 3 nozzles (1 for each grade). Where the separate mid grade tank may be the least used hence better chance of older gas.
Originally Posted By: Errtt
I always use the regular but recently I had to get mid grade because there was a "out of order" bag over the regular nozzle.
Don't know if it was a bad load or what, but my Toyota did not like it. It idled rough, felt like I was towing a car, and my mpg went down.
I posted about it,some say if using mid grade, to use the stations that have 1 nozzle for all grades that the chance of the system mixing the low & high (2-tanks) is better than having 3 nozzles (1 for each grade). Where the separate mid grade tank may be the least used hence better chance of older gas.
I think that your problem had more to do with the fuel from that gas station. When I see a gas station with pumps out of order, I go to another one, simple as that. Something is wrong with some part of that gas station's operation; if another is available without issues, why not go there instead? The price would be the same anyway.
I always use the regular but recently I had to get mid grade because there was a "out of order" bag over the regular nozzle.
Don't know if it was a bad load or what, but my Toyota did not like it. It idled rough, felt like I was towing a car, and my mpg went down.
I posted about it,some say if using mid grade, to use the stations that have 1 nozzle for all grades that the chance of the system mixing the low & high (2-tanks) is better than having 3 nozzles (1 for each grade). Where the separate mid grade tank may be the least used hence better chance of older gas.
I think that your problem had more to do with the fuel from that gas station. When I see a gas station with pumps out of order, I go to another one, simple as that. Something is wrong with some part of that gas station's operation; if another is available without issues, why not go there instead? The price would be the same anyway.
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The odds that that 87 is actually 87 and not 86 or 86.5 is not too good.
I love armchair excuses for things that have zero bearing in reality.
Car needs 87, use 87, you have to be a [censored] moron to think that the laws governing minimum octane requirements, minimum additive requirements, and minimum engine specifications somehow mean when they call for 87 that it actually needs 89.
But if you enjoy wasting money, ENJOY!
Thats why marketing rocks, people like to believe spending more means it has to be "doing something".
The odds that that 87 is actually 87 and not 86 or 86.5 is not too good.
I love armchair excuses for things that have zero bearing in reality.
Car needs 87, use 87, you have to be a [censored] moron to think that the laws governing minimum octane requirements, minimum additive requirements, and minimum engine specifications somehow mean when they call for 87 that it actually needs 89.
But if you enjoy wasting money, ENJOY!
Thats why marketing rocks, people like to believe spending more means it has to be "doing something".
Last engine I heard pre detonate was a 1983 F150 with a carb.
Modern cars don't, if yours is you have a problem and I would expect a CE light and code to come soon.
Modern ignition systems detect it and adjust before its audible. Which is why all the high compression cars out their owned by cheap people can get away with running 87 octane. 30 years ago they would have pre detonated like crazy.
Fuel companies have really done a good job marketing, all your really buying at the pump is fuel that is more resistant to burning, based on the compression ratio of your motor. 87 octane is more volatile than 93, etc. But the Shell marketing guys for example push V power, etc so you think your Civic will purr with a more expensive fuel. Classic up sell.
I know some very high performance cars do benefit from a higher octane fuel than 93, but they are rare. The 911 GT3 comes to mind, 108 octane is pretty good in those with the correct programing.
Modern cars don't, if yours is you have a problem and I would expect a CE light and code to come soon.
Modern ignition systems detect it and adjust before its audible. Which is why all the high compression cars out their owned by cheap people can get away with running 87 octane. 30 years ago they would have pre detonated like crazy.
Fuel companies have really done a good job marketing, all your really buying at the pump is fuel that is more resistant to burning, based on the compression ratio of your motor. 87 octane is more volatile than 93, etc. But the Shell marketing guys for example push V power, etc so you think your Civic will purr with a more expensive fuel. Classic up sell.
I know some very high performance cars do benefit from a higher octane fuel than 93, but they are rare. The 911 GT3 comes to mind, 108 octane is pretty good in those with the correct programing.
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That would be single blind.
I drove a 4Runner recently that pinged. But the temp gauge was just hitting the red zone. Otherwise I haven't heard ping in a while either.
Seems pretty obvious to me: if the car runs better on 89 (or 91), either by not pinging, not hesitating, or gets enough more mpg to recoup the cost--then run the higher octane. At some point some motors can build up carbon deposits which make them run differently than intended; or perhaps they were built prior to the ethanol invasion. Or otherwise have something amiss makes it only run 99% as well as it ought (some sensor slightly off, or maybe some timing chain stretch, or a little too much oil slipping past rings, who knows).
I know at altitude they do seem to run one or two octane numbers lower. Less dense air, so less peak cylinder pressures? Makes me wonder if they still have 91 octane for the turbo motors.
Finally, higher octane gas has less BTU's per gallon. Straight cut gasoline is something like 60 octane; they have to add stuff to make it higher. That stuff generally has less BTU's per volume. I've never heard of anyone using 91 octane in a motor that is happy on 87 and getting less mpg's, but it's theoretically possible.
Seems pretty obvious to me: if the car runs better on 89 (or 91), either by not pinging, not hesitating, or gets enough more mpg to recoup the cost--then run the higher octane. At some point some motors can build up carbon deposits which make them run differently than intended; or perhaps they were built prior to the ethanol invasion. Or otherwise have something amiss makes it only run 99% as well as it ought (some sensor slightly off, or maybe some timing chain stretch, or a little too much oil slipping past rings, who knows).
I know at altitude they do seem to run one or two octane numbers lower. Less dense air, so less peak cylinder pressures? Makes me wonder if they still have 91 octane for the turbo motors.
Finally, higher octane gas has less BTU's per gallon. Straight cut gasoline is something like 60 octane; they have to add stuff to make it higher. That stuff generally has less BTU's per volume. I've never heard of anyone using 91 octane in a motor that is happy on 87 and getting less mpg's, but it's theoretically possible.
hatterras -
Maybe it's your hearing that is going.
Cars stillping and knock. Retard systems with knock sensors attenuate it or make it stop , but of course they still knock.
The lowest octane fuel ignites/light off better/easier.
If we are NOT knocking, then it is always the best choice, esp in cold winter starting.
Maybe it's your hearing that is going.
Cars stillping and knock. Retard systems with knock sensors attenuate it or make it stop , but of course they still knock.
The lowest octane fuel ignites/light off better/easier.
If we are NOT knocking, then it is always the best choice, esp in cold winter starting.
Well never heard it on a stock street car, that didn't have a problem, or something else going on.
I think a lot of this is the placebo affect.
To the OP, lets get some data:
Fuel mileage average with your car using 87 and 91 over 5k miles per fuel. No fuel additives allowed, and you have to buy it from the same pump to minimize the tank to tank variances.
Secondly I want to see some data on performance. "Runs better" doesn't really mean a whole lot. How about dyno runs, or some timed 0-60 runs averaged of course?
Lastly what about VW? Does this car have an ECU that is maybe from Europe where they run a different grade of fuel, so its by default set up to take advantage of 91 octane? Kind of like a factory power tune.
That's the problem with this site, there is very rarely any data to back up anything. Its just I did this and I think it made my car feel good, so it must be good, and its good.
I think a lot of this is the placebo affect.
To the OP, lets get some data:
Fuel mileage average with your car using 87 and 91 over 5k miles per fuel. No fuel additives allowed, and you have to buy it from the same pump to minimize the tank to tank variances.
Secondly I want to see some data on performance. "Runs better" doesn't really mean a whole lot. How about dyno runs, or some timed 0-60 runs averaged of course?
Lastly what about VW? Does this car have an ECU that is maybe from Europe where they run a different grade of fuel, so its by default set up to take advantage of 91 octane? Kind of like a factory power tune.
That's the problem with this site, there is very rarely any data to back up anything. Its just I did this and I think it made my car feel good, so it must be good, and its good.
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Most stations run a 50/50 mix from both 87 and 93 tanks.
there USED to be a Midgrade tank, some places still have them.
Most midgrade tanks were drained and reused for Diesel.
there USED to be a Midgrade tank, some places still have them.
Most midgrade tanks were drained and reused for Diesel.
I wonder what the percentage from each service station tank is needed to raise 87 oct. gas to 89 oct. gas? 60% reg/40% prem, 70/30%? I would think every station would need to have the same ratio in order to raise the octane by 2. (This is assumimg 87/89/91 gas.) I only have gas guage and odometer for gas mileage. City/Hwy drives are not consistant. I have belief on what I experience. Most likely there are other factors involved.(Engine only has 4k miles as well.) If there's no long term neg. effects on the 2.5 engine, I believe I'll continue to use mid-grade gas. Thanks for your replies.
Originally Posted By: sparky123
I wonder what the percentage from each service station tank is needed to raise 87 oct. gas to 89 oct. gas? 60% reg/40% prem, 70/30%? I would think every station would need to have the same ratio in order to raise the octane by 2. (This is assumimg 87/89/91 gas.) I only have gas guage and odometer for gas mileage. City/Hwy drives are not consistant. I have belief on what I experience. Most likely there are other factors involved.(Engine only has 4k miles as well.) If there's no long term neg. effects on the 2.5 engine, I believe I'll continue to use mid-grade gas. Thanks for your replies.
Station I work at, the 2 big tanks route to a smaller (rougly a 200 gal tank) that mixes and sends to the pump.
Its a 55:45 ratio.
I wonder what the percentage from each service station tank is needed to raise 87 oct. gas to 89 oct. gas? 60% reg/40% prem, 70/30%? I would think every station would need to have the same ratio in order to raise the octane by 2. (This is assumimg 87/89/91 gas.) I only have gas guage and odometer for gas mileage. City/Hwy drives are not consistant. I have belief on what I experience. Most likely there are other factors involved.(Engine only has 4k miles as well.) If there's no long term neg. effects on the 2.5 engine, I believe I'll continue to use mid-grade gas. Thanks for your replies.
Station I work at, the 2 big tanks route to a smaller (rougly a 200 gal tank) that mixes and sends to the pump.
Its a 55:45 ratio.
Originally Posted By: GumbyJarvis
Most stations run a 50/50 mix from both 87 and 93 tanks.
there USED to be a Midgrade tank, some places still have them.
Most midgrade tanks were drained and reused for Diesel.
Yeah, I haven't seen a separate "midgrade" tank in decades. Even Sunoco, the Baskin-Robins of octane grading, just drew from two tanks in varying degrees in recent years.
Last multitank setup I recall was for the short-lived stint of leaded and unleaded regular back in the '70s . . . I don't remember if those stations carried midgrades as a result.
Too many tanks are too many tanks for retailers to have problems with.
FWIW, you can mix your own midgrade, and it is often a couple cents cheaper per gallon than using the pump's mixing valve for dedicated "midgrade".
Most stations run a 50/50 mix from both 87 and 93 tanks.
there USED to be a Midgrade tank, some places still have them.
Most midgrade tanks were drained and reused for Diesel.
Yeah, I haven't seen a separate "midgrade" tank in decades. Even Sunoco, the Baskin-Robins of octane grading, just drew from two tanks in varying degrees in recent years.
Last multitank setup I recall was for the short-lived stint of leaded and unleaded regular back in the '70s . . . I don't remember if those stations carried midgrades as a result.
Too many tanks are too many tanks for retailers to have problems with.
FWIW, you can mix your own midgrade, and it is often a couple cents cheaper per gallon than using the pump's mixing valve for dedicated "midgrade".
Sunoco and 7-11 here have like 7 different grades LOL
How does one put every fact from their experience and study into every post?
And back up all possible questions?
Answer: We can't.
Neither do those who find this 'fault' in others.
This is very different then not having hard information available when needed.
And back up all possible questions?
Answer: We can't.
Neither do those who find this 'fault' in others.
This is very different then not having hard information available when needed.
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Car needs 87, use 87, you have to be a [censored] moron to think that the laws governing minimum octane requirements, minimum additive requirements, and minimum engine specifications somehow mean when they call for 87 that it actually needs 89.
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Car needs minimum 87, book says do not use regular marked 86. Using premium is unnecessary and may cause a check engine light. I said my car runs better on 89 and gets better mileage and less pinging with 89. I don't know where you live but around here, people aren't all on the up and up. Who knows what garbage is in those tanks.
I don't feel I am wasting my money by spending 10 cents a gallon to keep my investment running the way I like it. I have never seen any marketing of Mid grade over Regular. I also waste money on Wax, water usage to keep it clean and top of the line tires.
Car needs 87, use 87, you have to be a [censored] moron to think that the laws governing minimum octane requirements, minimum additive requirements, and minimum engine specifications somehow mean when they call for 87 that it actually needs 89.
[/quote]
Car needs minimum 87, book says do not use regular marked 86. Using premium is unnecessary and may cause a check engine light. I said my car runs better on 89 and gets better mileage and less pinging with 89. I don't know where you live but around here, people aren't all on the up and up. Who knows what garbage is in those tanks.
I don't feel I am wasting my money by spending 10 cents a gallon to keep my investment running the way I like it. I have never seen any marketing of Mid grade over Regular. I also waste money on Wax, water usage to keep it clean and top of the line tires.
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My 98 Toyota Camry V6 is special. Manual says that it is designed to be ran on 87 Octane but then goes to say that the use of Premium fuel will result in improved engine performance.
We had the Camry since new and ran it on every which grade of fuel over the years. From years of back to back testing, i concluded that it DOES in fact run stronger with 93 Octane that we have in Florida. Runs just fine on 87 which is what we run 90% of the time nowadays because lets face it, it's an old beater and gets the cheap stuff.
Midgrade is for those who don't NEED Premium fuel but still want to use something a bit better then regular 87 Octane in their beloved car, so 89 Octane (which isn't technically midgrade anyway, so why call it midgrade???) is there for them as an option.
We had the Camry since new and ran it on every which grade of fuel over the years. From years of back to back testing, i concluded that it DOES in fact run stronger with 93 Octane that we have in Florida. Runs just fine on 87 which is what we run 90% of the time nowadays because lets face it, it's an old beater and gets the cheap stuff.
Midgrade is for those who don't NEED Premium fuel but still want to use something a bit better then regular 87 Octane in their beloved car, so 89 Octane (which isn't technically midgrade anyway, so why call it midgrade???) is there for them as an option.
I know my comments were based on mid grade being 89 octane with 10% ethanol content.
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