Premium Gas

[RubberFrog]

What total B.S. - what in depth testing and by whom and where can we find your source for this information?

There are two refineries for the entire state of California and so all the gasoline is the same regardless of the retail or fleet outlet. I can pay an extra 30 cents a gallon for the gas pumped at a Chevron station but only a guillible consumer would think they were getting more for their money.

What was important was taking the tetraethly lead out of gasoline in the 1970's as this was killing engines as well as poisoning the brains of children. After lead was no longer allowed engines lasted twice as long and crime rates dropped dramatically as children became young adults.

You don't know much about fuel.

Do you know why they call it top "tier"? Top tier fuel comes the upper part of the tank. Where do you suppose bottom tier comes from? Where do you suppose water and particulates settle in the storage tank? Which tier would you like to fuel your car with?

Additionally, top tier fuels use additives to improve the quality of the fuel. Do you suppose el-cheapo gas stations buying bottom tier fuel include any additives?

As far as lead... It was never there to boost octane. It was a lubricant and cooling agent to minimize wear on the exhaust valves. That's it. No performance boost, no extra power, nothing sexy at all. It didn't even burn up, it just shot right out the exhaust onto the road, and then washed into the storm drains.

 

[Sherman Bird]

Ethanol can go the way of lead too as far as I'm concerned.[/QUOTE]

Don't say that.... a corn farmer might read it and get all butt-hurt!

 

[Sherman Bird]

Gas is for motorcycles and generators.

Diesel is for trucks!

Other than that, all sides are covered already!

And Trix are for kids!

 

[Sherman Bird]

87 through 94 octane (or whatever) has the same energy density so using one over the other does not make your truck more powerful. However, a higher octane rating will decrease the ability of igniting prematurely creating piston vibration or knock (which is bad). Your engine has knock sensors that look for knock and will pull timing to help prevent this knock which will prevent your motor from making full power. Knock can happen at all rpms but frequently happens when lugging the motor (lots of fuel in lower gear or rpms). So - if you feel that it runs better (which I did with higher octane) its because it wasn't pulling timing when around town under part throttle accelerations and using lower gears (not downshifting).

Quality of fuel and ethanol play a larger part in energy density. Good fuel and lower or no ethanol is best.

Diesel fuel has I think 10 or 20% more energy than gasoline per volume which is one of the reasons they get better mileage (or can if the EPA would keep their hands out of the emission crap).

I do not know about FCA EEC fuel control systems strategy.... BUT GM's have a self check built into the strategy that sends a signal out to the ignition to way advance timing for just a nano second or so, or they did when I was still with them (pre 2000). This causes a very short pre-ignition knock that is so brief, you cannot hear it or even feel anything while driving. This in turn tests the integrity of the knock sensor and circuit.... thus: If you put 93 in a vehicle designed for 87, the expected knock will be absent... and the computer will assume the knock sensor is off line, and will retard timing. Now the vehicle runs a bit more sluggish than before... Cure is to simply go back to 87 octane if that's what is called for.

 

[NDanecker]

I do not know about FCA EEC fuel control systems strategy.... BUT GM's have a self check built into the strategy that sends a signal out to the ignition to way advance timing for just a nano second or so, or they did when I was still with them (pre 2000). This causes a very short pre-ignition knock that is so brief, you cannot hear it or even feel anything while driving. This in turn tests the integrity of the knock sensor and circuit.... thus: If you put 93 in a vehicle designed for 87, the expected knock will be absent... and the computer will assume the knock sensor is off line, and will retard timing. Now the vehicle runs a bit more sluggish than before... Cure is to simply go back to 87 octane if that's what is called for.

Respectfully, that is one of the most ridiculous routines to write into ECM code I have heard. Considering its coming from a GM and it being pre-2000 I am not surprised though. LOL

However, assuming it is true it shouldn't retard timing but instead blow a code and place the vehicle into limp mode if they feel its that important, and not continue to retard timing unbeknownst to the user.

 

[Sherman Bird]

Respectfully, that is one of the most ridiculous routines to write into ECM code I have heard. Considering its coming from a GM and it being pre-2000 I am not surprised though. LOL

However, assuming it is true it shouldn't retard timing but instead blow a code and place the vehicle into limp mode if they feel its that important, and not continue to retard timing unbeknownst to the user.

I only stated an old strategy from yesteryear as an amusing point as to the evolution of OBD engine management systems... sorry you got so torqued up!

 

[NDanecker]

I only stated an old strategy from yesteryear as an amusing point as to the evolution of OBD engine management systems... sorry you got so torqued up!

HAHA I'm not torqued up or upset at you or the control engineers who wrote this code. Actually I'm amused at how far we have come in just 20 years with respect to software, hardware and understanding what an internal combustion engine wants. If someone would have told you 20 years ago we'd be producing cars with 800+ HP from the factory would have you believed them?

Its all good my friend.

 

[Sherman Bird]

If someone would have told you 20 years ago we'd be producing cars with 800+ HP from the factory would have you believed them?

Its all good my friend. [/QUOTE]

Yes, because, 25 years ago, a GM field engineer was telling me about the "new design" small block under development... the 5.3, 6.0 family that went into trucks and Corvettes. Normally aspirated, that unit has 800 HP potential. So, yes, the big powered engines were on the drawing board and there were already prototypes out when he told me about them.

 

[dtru1222]

What total B.S. - what in depth testing and by whom and where can we find your source for this information?

There are two refineries for the entire state of California and so all the gasoline is the same regardless of the retail or fleet outlet. I can pay an extra 30 cents a gallon for the gas pumped at a Chevron station but only a guillible consumer would think they were getting more for their money.

What was important was taking the tetraethly lead out of gasoline in the 1970's as this was killing engines as well as poisoning the brains of children. After lead was no longer allowed engines lasted twice as long and crime rates dropped dramatically as children became young adults.

I have seen this lazy argument before. All it takes to disprove it is data logging gas from two different stations in your area. Your ST/LT knock will differ even on the same octane. I tried 93 shell vs chevron and found in all cases that chevron produced much lower ST/LT knock. Timing reduction due to knock absolutely makes a difference in power and MPG. You can keep echoing wrong statements all you want, the data will keep proving you wrong.

 

[crash68]

You can keep echoing wrong statements all you want, the data will keep proving you wrong.

Don't hold your breath on convincing the guy your replying to that he'll see the errors of his ways. He's been called out many times by multiple people on a wide range of topics for being FoS, sometimes multiple times in the same thread.

 

[4wdRookie]

I believe it was on BITOG when I was researching proper oil viscosity that I learned about Top Tier gas. That was a year ago, long before deciding to buy a truck, and I've been using TT ever since. Here is one source of information from Consumer Reports that I bookmarked. The article also has a short video which states their case on octane usage. That is, obviously, a bit more controversial. I don't think you have to be a CR member to access the page.

 

[RandomRam]

I settled on 89 for my 6.4. No noticeable difference in power. MDS is smoother and seems to stay engaged for longer than it did on 87. Never noticed a difference between 89 and 91.

 

[kad]

I have a 1500 and I believe 89+ is recommended. I have used 87 and 91 and noticed 0 difference.

My '14 5.7 calls for 89 with 87 being "acceptable if 89 is not available" I've also run a couple of tanks of 91 "No Ethanol" just to see if it made a mileage difference (it didn't). I'm in southern NY so most stations only have 87, 89 & 93. A very small number of stations carry the 91 No Ethanol, which I usually only buy for the lawn equipment.

-K

 

[4wdRookie]

My '14 5.7 calls for 89 with 87 being "acceptable if 89 is not available" I've also run a couple of tanks of 91 "No Ethanol" just to see if it made a mileage difference (it didn't). I'm in southern NY so most stations only have 87, 89 & 93. A very small number of stations carry the 91 No Ethanol, which I usually only buy for the lawn equipment.

For over 15 years our vehicle octane recommendations have been 87. Having a new Hemi V8 is a whole new ball game. Like you my owner's manual states "89 Octane Recommended - 87 Octane Acceptable". So for my first fill I went with 89, 40 cents more per gallon over 87. I never even considered that 89 was mixed at the pump and that the station owner can control that mix. So it's 87 for me from here on out.

 

[tidefan1967]

Not exactly the same thing but we had a new Shell station open up a mile down the street so I went down there to check it out and look what I found:

View attachment 220142
First time I’ve seen any ethanol free 89 around here and I’ll be damned it’s not too expensive either. Might have to try a few tanks and see what happens.

 

[seabrook]

Ethanol is good for removing moisture in your fuel system and excellent octane enhancement but is terrible for anything that sits

 

[Octane]

I use methanol for condensation in the tank.Works in airbrakes too.

 

[tidefan1967]

Ethanol is good for removing moisture in your fuel system and excellent octane enhancement but is terrible for anything that sits

You mean ethanol is good at attracting water into your fuel system right?

 

[Octane]

When ethanol and gas mixes begin to break down there is water that comes from the alcohol.But when fresh it actually disperses any water in the tank into smaller droplets, that go on thru and burn off unnoticed

 

[Sherman Bird]

When ethanol and gas mixes begin to break down there is water that comes from the alcohol.But when fresh it actually disperses any water in the tank into smaller droplets, that go on thru and burn off unnoticed

Where do you get this (mis) information?