OK Tom, Let's Talk GAS!!

[Canyon707]

DC did my computer with 91 octane I was just wondering if there might be a slight advantage using 93 at the drag strip. I guess I will just keep running 91 it seems fine no detonation.

 

[GTS Bruce]

Looked at the top tier list. Only one in my area on the list is mobil. I usualy use sunocco and its on the list for Canada but not the US? Both 93 octane in my area. GTS Bruce

 

[Tom F&L GoR]

Yes, more resistance to preignition with 93 octane. Chances are you won't feel any difference with 93. But you can hook up a computer and watch how much timing your knock sensors are pulling. If 91 octane doesn't pull any timing, then 93 will be no added benefit.

I refine the crude that makes gasoline, and I still don't understand the "Nitrogen enriched fuel" marketing. Nitrogen is something we remove from oil when we treat it. Essentially the best oil would have 0ppm N2 in the product. We treat it higher than that, because they don't want to waste money over treating, when industry only demands a minimum of say 5ppm for example. So "Nitrogen Enriched", just tells me that the refinery relaxed their minimum targets, and you're now getting worse gasoline.

Nitrogen is an inert element. So in theory any nitrogen you add to your gas, would only serve to take up volume space that could be filled with gasoline, causing you to burn more gas to create the same power.

And wow, this is an old thread................

Different type of nitrogen. These are soluble, not solid or gaseous versions. They are the massive majority of many kinds of cleaning addiitves.

Think of ammonia, the common cleaner. Works pretty good, and is the simplest form of such a nitrogen compound. To make it work in fuels, chemists need to attach a "tail" so it becomes soluble in gasoline. And then to make it "work" it has to lose it's tail at the appropriate temperature, so the connection between the nitrogen "head" and the hydrocarbon-like "tail" comes apart. At this point there are many, many versions of "aminated" additives; polyether amines such as in Chevron gasoline and Techron additive, polybutene amines as sold by other additive companies, etc, etc.

The same holds for lube oil additives; there is a different type of tail, a different type of connection, but still some kind of nitrogen-bearing head to do the cleaning.

 

[Viktimize]

Different type of nitrogen. These are soluble, not solid or gaseous versions. They are the massive majority of many kinds of cleaning addiitves.

Think of ammonia, the common cleaner. Works pretty good, and is the simplest form of such a nitrogen compound. To make it work in fuels, chemists need to attach a "tail" so it becomes soluble in gasoline. And then to make it "work" it has to lose it's tail at the appropriate temperature, so the connection between the nitrogen "head" and the hydrocarbon-like "tail" comes apart. At this point there are many, many versions of "aminated" additives; polyether amines such as in Chevron gasoline and Techron additive, polybutene amines as sold by other additive companies, etc, etc.

The same holds for lube oil additives; there is a different type of tail, a different type of connection, but still some kind of nitrogen-bearing head to do the cleaning.

I see. Thanks for the detailed explanation.

 

[TrackAire]

Tom,

Thanks for all the detailed answers!!

I just picked up a 91 Suburban with a 1/4 tank of 2 year old gas. I'm going to run it dry and then fill the tank to get the truck smogged.

Is it better to run low octane or high octane when getting a smog check on a questionable vehicle? My gut says 87 since it burns easier (and in my mind more complete).

The truck is stock, Chevy 350 TBI with the old style pancake catalytic converter.

Is there anything else you would recommed to add in the first tank with the fresh fuel (additive-wise that would help it pass smog)? I know in previous discussions that additives clean and can get rid of hot spots that cause pre-ignition....but can these additives also increase the measured smog level in hyper sensitive California?

Look forward to your response.

Cheers,
George

 

[plumcrazy]

DC did my computer with 91 octane I was just wondering if there might be a slight advantage using 93 at the drag strip. I guess I will just keep running 91 it seems fine no detonation.

let tom answer to be sure but id say no gain unless you made a tune change for it.

 

[Tom F&L GoR]

Tom,

Thanks for all the detailed answers!!

I just picked up a 91 Suburban with a 1/4 tank of 2 year old gas. I'm going to run it dry and then fill the tank to get the truck smogged.

Is it better to run low octane or high octane when getting a smog check on a questionable vehicle? My gut says 87 since it burns easier (and in my mind more complete).

The truck is stock, Chevy 350 TBI with the old style pancake catalytic converter.

Is there anything else you would recommed to add in the first tank with the fresh fuel (additive-wise that would help it pass smog)? I know in previous discussions that additives clean and can get rid of hot spots that cause pre-ignition....but can these additives also increase the measured smog level in hyper sensitive California?

Look forward to your response.

Cheers,
George

George, I don't know if you would have the time for this, but I'm a little nervous in running two year old fuel down to empty. The fuel has lost all the lighter components, the heavy ones left behind will make the engine run poorly, be hard to start, and maybe smell bad. Plus, if it sets any codes or pending codes because of misfires, they will show up later even with the "good" fuel tank. I would rather you fill the tank ASAP and run it down, maybe with a bottle of (suggestion, not endorsement) Techron, then refill for the inspection.

Good news is that TBI plugs less and is easier to clean up with additives.

Low octane would be better because it's likely more volatile and will burn easily. CA fuels are probably all oxygenated, so be on the look out for plugged fuel filters after such a long period. High fuel flow rates and a hotter combustion chamber ("Italian" tune up <-- is that a negative stereotype comment? Sorry.) would help rinse things out.

Good luck.

 

[Tom F&L GoR]

DC did my computer with 91 octane I was just wondering if there might be a slight advantage using 93 at the drag strip. I guess I will just keep running 91 it seems fine no detonation.

No, probably not. Higher octane is typically less volatile, and there has to be enough that vaporizes for the entire charge to burn efficiently. Unless the compression ratio was also increased (heat of compression would help vaporization) the 91 is better.

 

[TrackAire]

Thanks Tom,

I'll follow your advise.

Cheers,
George

 

[Canyon707]

ditto Tom Thanks

 

[pure zen]

Thanks guys,,,,all good information.





Shell

The above video, is worth a look.

 

[1994viper]

Tom, what gas do you feed your Viper?
And what Gas you are trying to avoid?

 

[Golfer15]

Wow, she has the biggest...

watch on her wrist!

(See Dave, AIDA works!)

She's wearing a watch ???

 

[Tom F&L GoR]

Tom, what gas do you feed your Viper?
And what Gas you are trying to avoid?

My company sells additives to global and NAFTA brands, to terminals that supply local stations, and to chemical distributors that service the regional market. I'm going to sidestep that question.

I would avoid stations with really low volume sales; if the outside of the station looks crappy, then the tanks underground might be also; and if you are looking for more additive than the minimum, keep your eyes open for advertising. If the brand does not advertise (other than pump toppers) then they aren't spending on extra additives, either.

All gasolines are fungible; they come out of the same pipeline and into the same terminal and only get different additives when the tank truck pulls up to get filled. Buying a cheap premium means 93 octane and minimal cleaning additives, buying a brand name regular means 87 octane and additives to clean injectors, valves, etc. You have to disconnect those features - higher (or lower) octane has no relation to cleanliness of the engine.