1996 LT1 93 Octane Sunoco
Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
I have heard that rumor but from what I see of Costco, they have filters that they have to monitor the flow rate of. So I think you are relatively safe. You have the sock filter in the tank, the filter after the pump and the one in the injector.
Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
Constant low fuel levels will prematurely kill fuel pumps. It is best to keep the pump submerged and a have enough fuel in the tank to dissipate the heat of the returned fuel. Now debris and water absorbtion can also cause issues with low tank levels but heat is the real killer.
I delivered pizzas for 7 years and witnessed all sorts of co-workers burning up pumps. Turns out chronically putting 5 bucks in the tank for prolonged periods of time isn't the best idea.
That being said, I drive my 84 with about 3-8 gallons in the tank. I haven't filled the tank fully in about 2 years. The main reason is weight savings for racing. If I burn a pump up, big deal, I would rather not have the extra 80-110 lbs onboard. With my daily cars I fill them up when I get to 1/4 - 1/8 of tank.
I delivered pizzas for 7 years and witnessed all sorts of co-workers burning up pumps. Turns out chronically putting 5 bucks in the tank for prolonged periods of time isn't the best idea.
That being said, I drive my 84 with about 3-8 gallons in the tank. I haven't filled the tank fully in about 2 years. The main reason is weight savings for racing. If I burn a pump up, big deal, I would rather not have the extra 80-110 lbs onboard. With my daily cars I fill them up when I get to 1/4 - 1/8 of tank.
Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
Wawa is equal to quick check (you have them out there right?) I had a friend who was a dispatcher for their fuel deliveries, all the trucks came from at that point, mobil or one of their subsidiaries. One of my friends in weights and measures said their fuel runs on the low side of what's allowed for ethanol content as well. My understanding is they just don't feel like paying for the top teir license, but it does meet the qualifications. Even if it doesn't, they turn over their tanks 4 times a day. So its about as fresh as I can get lol. 
If Costco is somehow top teir, they are as well. I've watched the truck pull out Costco and go across the street and fill their pumps too. 
It is and isn't. Some vehicles I've owned don't really have a bucket around the fuel pump. In turn anything below 1/3 resulted in it being mostly unsubmerged. I put 3 pumps in one and every time it crapped out was a result of filling the tank. I made it about 5 feet from the station pump before it went dead. The hot to cold definitely is something on certain vehicles. Later models revised the tank so the pump sat in a bowl and was mostly submerged unless on reserve. There is some bit of truth to it. But I have 5 others that I don't worry about lol. Hell I've run them dry several times. Even the 84 keeps fuel around the pump until you're insanely low.
If Costco is somehow top teir, they are as well. I've watched the truck pull out Costco and go across the street and fill their pumps too. It is and isn't. Some vehicles I've owned don't really have a bucket around the fuel pump. In turn anything below 1/3 resulted in it being mostly unsubmerged. I put 3 pumps in one and every time it crapped out was a result of filling the tank. I made it about 5 feet from the station pump before it went dead. The hot to cold definitely is something on certain vehicles. Later models revised the tank so the pump sat in a bowl and was mostly submerged unless on reserve. There is some bit of truth to it. But I have 5 others that I don't worry about lol. Hell I've run them dry several times. Even the 84 keeps fuel around the pump until you're insanely low.
How does the "bucket" work? From what I understand, it is a baffle to prevent fuel sloshing around and starving the pump and not really keep it submerged.
Le Mans Master
Joined: Aug 2017
Posts: 6,943
Likes: 1,490
From: New Jersey
If that makes sense. The car was also on stands and angled so that could have done it.
Le Mans Master
Joined: Aug 2017
Posts: 6,943
Likes: 1,490
From: New Jersey
Tech Contributor
Joined: Jun 2004
Posts: 20,910
Likes: 962
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Here in Northern Virginia the Costco gas station claims it's regular gas has 4 times the cleaners that are required to keep your Fuel system cleaner.
I use Sunoco gas almost exclusively in my high compression 427 as it has the highest octane available locally without buying racing fuel. My engine has L88 pistons and matching cast iron heads (unlike the real L88's) and my engine needs over 100 octane to run normally. In this area they don't sell any non-oxygenated fuels at all. We have to go 50 miles to get it... When I need it I squirt water/methanol into the engine to cool it's fire and raise the octane to 116. It is turned on after the engine is hot and only under a load. Beats the heck out of buying racing gas when you can inject windshield washer fluid into your engine and make it happy. Windshield washer fluid is roughly 50/50 water and methanol so it works great in my fuel system.
I love to watch people putting the Highest Octane fuel into an Asian econobox/racecar as they swear it makes their low compression "car" go faster. Not to many people seem to be aware that higher octane fuel burns slower than the cheap stuff.
My daughter has a 2011 Camaro and she uses regular normally. Her Camaro does get better mileage when it uses Higher octane gasoline, with regular gas you sacrifice a little power and economy. On the highway it gets close to 30 mpg with premium, with regular you are down to 23-25 mpg. It doesn't hurt the car to use regular, it just doesn't make as much power with regular. Her car has the 3.6 liter V6 with Direct Injection and Variable Valve Timing and makes 313 horsepower with a six speed transmission. It is not a Corvette but very close, her next car will be a Corvette she swears!
Now I have to figure out what to do with all the Tetra-ethyl Lead Concentrate I have in my garage. I now have a EFI system on my C3 and have a O2 sensor in the exhaust. I heard that the lead would kill the O2 in a hurry. I bought a lot of the stuff at Corvettes@Carlisle and it does work but you have to wear an apron and a mask to keep it from touching you and whatever you do DON'T get it on your Paint-job. It was my old back up before the water/methanol injection systems appeared. It works if you have a need for it. Just nasty stuff in general.
I know which days the gas is delivered to my Sunoco so I never go on those days. I let it settle for about 24 hours before pumping it into my Cars. I also added an extra filter inline to protect my engine from any crap in the fuel.
While driving coast to coast a few years ago I saw 100 octane fuel available at a gas station off the interstate. It wasn't even that expensive compared to the premium fuels. I wish I had one of those nearby....
If you don't need the Octane don't waste the money on the premium fuels.
If you don't worry about the cost you can send the extra money to me!
For a few bucks we can find a "Witch Doctor" to make your car faster...
I use Sunoco gas almost exclusively in my high compression 427 as it has the highest octane available locally without buying racing fuel. My engine has L88 pistons and matching cast iron heads (unlike the real L88's) and my engine needs over 100 octane to run normally. In this area they don't sell any non-oxygenated fuels at all. We have to go 50 miles to get it... When I need it I squirt water/methanol into the engine to cool it's fire and raise the octane to 116. It is turned on after the engine is hot and only under a load. Beats the heck out of buying racing gas when you can inject windshield washer fluid into your engine and make it happy. Windshield washer fluid is roughly 50/50 water and methanol so it works great in my fuel system.
I love to watch people putting the Highest Octane fuel into an Asian econobox/racecar as they swear it makes their low compression "car" go faster. Not to many people seem to be aware that higher octane fuel burns slower than the cheap stuff.
My daughter has a 2011 Camaro and she uses regular normally. Her Camaro does get better mileage when it uses Higher octane gasoline, with regular gas you sacrifice a little power and economy. On the highway it gets close to 30 mpg with premium, with regular you are down to 23-25 mpg. It doesn't hurt the car to use regular, it just doesn't make as much power with regular. Her car has the 3.6 liter V6 with Direct Injection and Variable Valve Timing and makes 313 horsepower with a six speed transmission. It is not a Corvette but very close, her next car will be a Corvette she swears!
Now I have to figure out what to do with all the Tetra-ethyl Lead Concentrate I have in my garage. I now have a EFI system on my C3 and have a O2 sensor in the exhaust. I heard that the lead would kill the O2 in a hurry. I bought a lot of the stuff at Corvettes@Carlisle and it does work but you have to wear an apron and a mask to keep it from touching you and whatever you do DON'T get it on your Paint-job. It was my old back up before the water/methanol injection systems appeared. It works if you have a need for it. Just nasty stuff in general.
I know which days the gas is delivered to my Sunoco so I never go on those days. I let it settle for about 24 hours before pumping it into my Cars. I also added an extra filter inline to protect my engine from any crap in the fuel.
While driving coast to coast a few years ago I saw 100 octane fuel available at a gas station off the interstate. It wasn't even that expensive compared to the premium fuels. I wish I had one of those nearby....
If you don't need the Octane don't waste the money on the premium fuels.
If you don't worry about the cost you can send the extra money to me!
For a few bucks we can find a "Witch Doctor" to make your car faster...
Talked to a fuel supplier guy at a PRI show years ago, and he said it's an old wives' tale.
Regardless, I'd like to see some technical documentation.
Thread Starter
Instructor
Joined: May 2020
Posts: 159
Likes: 17
From: Northeast, Ohio
Hey Tom, some good stuff there especially about the scan tool and knock counts. Advice on which one I should purchase?
I was pretty much asking him on which one he uses...
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Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
I have four. For OBD-II;
I have a crappy, Actron code reader -it won't read knock counts, but it's quick and easy for some basic things.
I have a Autel scan tool. it will read knock counts and make a nice graph for you too. It's a good tool, but it is slow.
I have a Snap-On Modis Ultra. Not surprisingly, this one is the fastest, bestest, most expensive-est.
For OBD I, I have an old but very functional, OTC Monitor 4000e. It's totally awesome for it's time and will do data stream, in any display you want showing 8 functions at a time. It will "snap shot"/freeze frame events. Great tool for the era.
I have a crappy, Actron code reader -it won't read knock counts, but it's quick and easy for some basic things.
I have a Autel scan tool. it will read knock counts and make a nice graph for you too. It's a good tool, but it is slow.
I have a Snap-On Modis Ultra. Not surprisingly, this one is the fastest, bestest, most expensive-est.
For OBD I, I have an old but very functional, OTC Monitor 4000e. It's totally awesome for it's time and will do data stream, in any display you want showing 8 functions at a time. It will "snap shot"/freeze frame events. Great tool for the era.
Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
Safety Car
Joined: May 2001
Posts: 4,759
Likes: 1,647
From: Fairfax Virginia
Hello 69427,
You are very likely correct about the gasoline stories we hear.
In the case of this particular Sunoco I am friends with a mechanic and he said that the owners will not fill their own cars within hours after a truck delivers fuel.
Even they choose to wait for it to settle despite this likely being a "Story". I just play it safe by following their actions.
If Ethanol is so expensive then why do we pay ridiculous prices for plain old pure gasoline without any expensive and damaging alcohol? I would expect pure gasoline to be cheaper than oxygenated fuels.
I have used my Ethanol tester to see just how much they are adding to our gasoline. My Sunoco stays at slightly less than 10% where I have seen 12-15% at other stations with signs displaying that their fuel is 10% ethanol.
You are very likely correct about the gasoline stories we hear.
In the case of this particular Sunoco I am friends with a mechanic and he said that the owners will not fill their own cars within hours after a truck delivers fuel.
Even they choose to wait for it to settle despite this likely being a "Story". I just play it safe by following their actions.
If Ethanol is so expensive then why do we pay ridiculous prices for plain old pure gasoline without any expensive and damaging alcohol? I would expect pure gasoline to be cheaper than oxygenated fuels.
I have used my Ethanol tester to see just how much they are adding to our gasoline. My Sunoco stays at slightly less than 10% where I have seen 12-15% at other stations with signs displaying that their fuel is 10% ethanol.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Likely because that is the "standard brew" that refineries are doing, so it probably costs more to get a truck to fill, and deliver with something that every other gas station isn't getting.
Thread Starter
Instructor
Joined: May 2020
Posts: 159
Likes: 17
From: Northeast, Ohio
I have four. For OBD-II;
I have a crappy, Actron code reader -it won't read knock counts, but it's quick and easy for some basic things.
I have a Autel scan tool. it will read knock counts and make a nice graph for you too. It's a good tool, but it is slow.
I have a Snap-On Modis Ultra. Not surprisingly, this one is the fastest, bestest, most expensive-est.
For OBD I, I have an old but very functional, OTC Monitor 4000e. It's totally awesome for it's time and will do data stream, in any display you want showing 8 functions at a time. It will "snap shot"/freeze frame events. Great tool for the era.
I have a crappy, Actron code reader -it won't read knock counts, but it's quick and easy for some basic things.
I have a Autel scan tool. it will read knock counts and make a nice graph for you too. It's a good tool, but it is slow.
I have a Snap-On Modis Ultra. Not surprisingly, this one is the fastest, bestest, most expensive-est.
For OBD I, I have an old but very functional, OTC Monitor 4000e. It's totally awesome for it's time and will do data stream, in any display you want showing 8 functions at a time. It will "snap shot"/freeze frame events. Great tool for the era.
Tech Contributor
Joined: Jun 2004
Posts: 20,910
Likes: 962
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Hello 69427,
You are very likely correct about the gasoline stories we hear.
In the case of this particular Sunoco I am friends with a mechanic and he said that the owners will not fill their own cars within hours after a truck delivers fuel.
Even they choose to wait for it to settle despite this likely being a "Story". I just play it safe by following their actions.
If Ethanol is so expensive then why do we pay ridiculous prices for plain old pure gasoline without any expensive and damaging alcohol? I would expect pure gasoline to be cheaper than oxygenated fuels.
I have used my Ethanol tester to see just how much they are adding to our gasoline. My Sunoco stays at slightly less than 10% where I have seen 12-15% at other stations with signs displaying that their fuel is 10% ethanol.
You are very likely correct about the gasoline stories we hear.
In the case of this particular Sunoco I am friends with a mechanic and he said that the owners will not fill their own cars within hours after a truck delivers fuel.
Even they choose to wait for it to settle despite this likely being a "Story". I just play it safe by following their actions.
If Ethanol is so expensive then why do we pay ridiculous prices for plain old pure gasoline without any expensive and damaging alcohol? I would expect pure gasoline to be cheaper than oxygenated fuels.
I have used my Ethanol tester to see just how much they are adding to our gasoline. My Sunoco stays at slightly less than 10% where I have seen 12-15% at other stations with signs displaying that their fuel is 10% ethanol.
Would just like to see any actual engineering/technical documentation regarding this.
I've looked over the years, but have only seen bits and pieces of info regarding burn rate influences of the specific additives in the fuel.
Le Mans Master
Joined: Aug 2017
Posts: 6,943
Likes: 1,490
From: New Jersey
I was addressing your claim that high octane fuel burns slower than regular grade.
Would just like to see any actual engineering/technical documentation regarding this.
I've looked over the years, but have only seen bits and pieces of info regarding burn rate influences of the specific additives in the fuel.
Would just like to see any actual engineering/technical documentation regarding this.
I've looked over the years, but have only seen bits and pieces of info regarding burn rate influences of the specific additives in the fuel.
Safety Car
Joined: May 2001
Posts: 4,759
Likes: 1,647
From: Fairfax Virginia
Hello again 69427,
I took a quick look for evidence and I found this article:
"Higher octane gas is processed through additional steps that further refine the blend and cause it to burn more slowly than lower octanes. ... Because higher octane gas burns slower, it is more resistant to knock when subjected to higher RPM and cylinder pressures. Compression ratios also factor into cylinder pressures. Apr 11, 2014"
Here is another good article from Wikipedia.
"Because octane is a measured and/or calculated rating of the fuel's ability to resist auto-ignition, the higher the octane of the fuel, the harder that fuel is to ignite and the more heat is required to ignite it. The result is that a hotter ignition spark is required for ignition."
I spent some time learning about this before I re-built my 427. I bought the pistons and thought what if? 12.25-1 compression with the closed chamber cylinder heads were known back in the 1960's to make power. My heads (GM part 3931063) are a pair of cast iron heads with work to clean up the flow. My timing was 38* at 3000 and I did not use my distributor Vacuum advance (Bad idea). The Corvette has an original L88 hood from a L88 Race car that was destroyed in the early 1970's. I have the hood and the accessories to use it. I have the wedding cake on the engine and it seals to my Hood and this allows very cool air to enter the cylinder and make even more power and reduce the likely hood of detonation.
Today with over 8000 miles on this engine I am switching it over to a EFI system.
I took a quick look for evidence and I found this article:
"Higher octane gas is processed through additional steps that further refine the blend and cause it to burn more slowly than lower octanes. ... Because higher octane gas burns slower, it is more resistant to knock when subjected to higher RPM and cylinder pressures. Compression ratios also factor into cylinder pressures. Apr 11, 2014"
Tech 101 - Octane: the facts and the fiction behind those ...
Here is another good article from Wikipedia.
"Because octane is a measured and/or calculated rating of the fuel's ability to resist auto-ignition, the higher the octane of the fuel, the harder that fuel is to ignite and the more heat is required to ignite it. The result is that a hotter ignition spark is required for ignition."
I spent some time learning about this before I re-built my 427. I bought the pistons and thought what if? 12.25-1 compression with the closed chamber cylinder heads were known back in the 1960's to make power. My heads (GM part 3931063) are a pair of cast iron heads with work to clean up the flow. My timing was 38* at 3000 and I did not use my distributor Vacuum advance (Bad idea). The Corvette has an original L88 hood from a L88 Race car that was destroyed in the early 1970's. I have the hood and the accessories to use it. I have the wedding cake on the engine and it seals to my Hood and this allows very cool air to enter the cylinder and make even more power and reduce the likely hood of detonation.
Today with over 8000 miles on this engine I am switching it over to a EFI system.
Tech Contributor
Joined: Jun 2004
Posts: 20,910
Likes: 962
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Hello again 69427,
I took a quick look for evidence and I found this article:
"Higher octane gas is processed through additional steps that further refine the blend and cause it to burn more slowly than lower octanes. ... Because higher octane gas burns slower, it is more resistant to knock when subjected to higher RPM and cylinder pressures. Compression ratios also factor into cylinder pressures. Apr 11, 2014"
Here is another good article from Wikipedia.
"Because octane is a measured and/or calculated rating of the fuel's ability to resist auto-ignition, the higher the octane of the fuel, the harder that fuel is to ignite and the more heat is required to ignite it. The result is that a hotter ignition spark is required for ignition."
I spent some time learning about this before I re-built my 427. I bought the pistons and thought what if? 12.25-1 compression with the closed chamber cylinder heads were known back in the 1960's to make power. My heads (GM part 3931063) are a pair of cast iron heads with work to clean up the flow. My timing was 38* at 3000 and I did not use my distributor Vacuum advance (Bad idea). The Corvette has an original L88 hood from a L88 Race car that was destroyed in the early 1970's. I have the hood and the accessories to use it. I have the wedding cake on the engine and it seals to my Hood and this allows very cool air to enter the cylinder and make even more power and reduce the likely hood of detonation.
Today with over 8000 miles on this engine I am switching it over to a EFI system.
I took a quick look for evidence and I found this article:
"Higher octane gas is processed through additional steps that further refine the blend and cause it to burn more slowly than lower octanes. ... Because higher octane gas burns slower, it is more resistant to knock when subjected to higher RPM and cylinder pressures. Compression ratios also factor into cylinder pressures. Apr 11, 2014"
Tech 101 - Octane: the facts and the fiction behind those ...
Here is another good article from Wikipedia.
"Because octane is a measured and/or calculated rating of the fuel's ability to resist auto-ignition, the higher the octane of the fuel, the harder that fuel is to ignite and the more heat is required to ignite it. The result is that a hotter ignition spark is required for ignition."
I spent some time learning about this before I re-built my 427. I bought the pistons and thought what if? 12.25-1 compression with the closed chamber cylinder heads were known back in the 1960's to make power. My heads (GM part 3931063) are a pair of cast iron heads with work to clean up the flow. My timing was 38* at 3000 and I did not use my distributor Vacuum advance (Bad idea). The Corvette has an original L88 hood from a L88 Race car that was destroyed in the early 1970's. I have the hood and the accessories to use it. I have the wedding cake on the engine and it seals to my Hood and this allows very cool air to enter the cylinder and make even more power and reduce the likely hood of detonation.
Today with over 8000 miles on this engine I am switching it over to a EFI system.
I found several errors in that write-up that just left me shaking my head.
I'm still looking for an in-depth write-up that explains combustion burn rates versus octane/additives, but in the mean time here's a writeup from a source with a bit more credibility.
https://www.sunocoracefuels.com/tech.../beyond-octane
If and when I find a good write-up on this topic, I'll post it.
Le Mans Master
Joined: Aug 2017
Posts: 6,943
Likes: 1,490
From: New Jersey
Not trying to be disrespectful here, but the Hemmings article is a good example of why it's generally an unproductive use of one's time reading "technical" stuff from people who appear to be journalists, not engineers or technical types.
I found several errors in that write-up that just left me shaking my head.
I'm still looking for an in-depth write-up that explains combustion burn rates versus octane/additives, but in the mean time here's a writeup from a source with a bit more credibility.
https://www.sunocoracefuels.com/tech.../beyond-octane
If and when I find a good write-up on this topic, I'll post it.
I found several errors in that write-up that just left me shaking my head.
I'm still looking for an in-depth write-up that explains combustion burn rates versus octane/additives, but in the mean time here's a writeup from a source with a bit more credibility.
https://www.sunocoracefuels.com/tech.../beyond-octane
If and when I find a good write-up on this topic, I'll post it.
Race Director
Joined: Dec 2002
Posts: 13,348
Likes: 233
From: SCMR Rat Pack'r Charter Member..Great Bend KS
Drifting
Joined: Jun 2018
Posts: 1,678
Likes: 229
From: Michigan
Kyle is correct on the definition of octane. He then uses a commonly-misused term: "pre-detonation". There is pre-ignition, and there is detonation. They are two very different phenomenons that can result in engine damage. As a retired engineer, I tend to get hung up on the use of correct terminology........
.