..........and on and on goes the discussion........ and b4 long we're into a big battle. -- not good...

Dave, what I've gleaned from this talk is that there is a place for regular, low octane fuel, and there is a place for high octane fuel , and some in-between-octanes.
The use of High octane in an engine that only requires low octane is unnecessary and more than that a waste and it seems counterproductive.

I think everyone is saying the same thing so let's not misunderstand what's going on here.
As far as I can tell, there's nothing new being stated here, so let's leave it at that and leave it be.
We appreciate your and Jeff's input on the subject as well as everybody else's --but we don't need any more big arguments.....

.. As to where this thread should be....let me worry about that. I'm quite capable of moving threads if and when the need arises.

Colin.

 

Colin. IMHO only so don't hang me

I think the title of the thread is misleading. You have to dig into the article before getting the gist of it.

Anyhoo here's my point. On on hand, we are supposed to use oil that has qualities well above and beyond the needs of our engines (unless boosted). Especially when most of us change it every 3-5k anyway.

But on the other hand, it's suggested we only use fuel that's merely "adequate"? IMHO using a fuel that will allow us to run the ecu's most aggressive ign timing maps is as important or more important than using a synthetic oil.

Thanks

 

I don't see the point of this post either, all G's require premium, so this generic article about the qualities of regular have no relevance to any of us. If anything it should be in off topic since it has no direct application to the VQ which requires premium only

 

Well put, Jeff.. and a fair question.

I'll let the experts offer answers...........all I ask is for civility in the discussion.

Colin.

 

Do you have any way to back up this statement? I went to engineering school with many mechanical (some SAE) engineers who would disagree with that statement, especially when building and testing jet engines / other mechanical engines. I'm not trying to flame, I'm just curious if you can link me to your sources.

Again I will have to disagree with you here. From both my empirical testing (trips of the same distance, using cruise control and climate coontrol set to the same and approx same outside temperature) I have noticed an increase in mpg. Also while in school I worked on a hybrid vehicle (the Future Truck competition) and we have data to disagree with you that premium can both offer additional MPG and performance due to being used in a higher compression engine. You may have data that backs your statements. That's the fun of science - it's not always perfect and not all scenarios are created equal.

What is your law of physics you are stating here? Higher BTU content simply is the heat that something can produce. What is the efficiency of a gasoline engine - pretty low - as the majority of energy is released as heat. So simply on this statement, what does the heat content have to do with the explosive capability of something? I would say the volitity of the substance is more important, as well as the condition of how cleanly the gasoline is converted into gas, and not into carbon (which will lead to buildup).

Premium fuel has always had its place for enthusiasts who tweak and modify their engines - the 100 octane fuel you can see located near race tracks definitely again from my personal experience and what I've seen does indeed give you a performance boost. However on the smaller scale, i.e. the prius, the additional cleaning agents (techron for instance - or higher concentration) has over and over again proved to me to be beneficial on a long trip where the engine remains at a constant RPM state for several hours. Personally I enjoy the ability of the prius to use the cheapest regular out there since the electric portion def will help compensate the already dismal 80hp engine.

Can you please post a link to a SAE article? I know of FAQ.org, but I'd like some engineering validity behind something if possible (being an engineer myself).

 

Redlude--
In case you missed it, I've already said my peace of where this should be, and right now it's here because I want it here.......

post #31......

This, or any other issue, isn't subject to public vote. You're here by invitation only.....

Colin

 

Premium gas has no extra cleaners. PERIOD. why would it? I'm a chemical engineer, so I would say I understand the petroluem refining industry pretty well. The differences are in the octane additives, no differences in the detergent levels.

Once again, only applicable for engines that can use more a more aggressive timing map for the higher octane gasoline. In a low compression engine with conservative timing, no increase will be seen.


BTU ratings ARE the measure of how explosive a mixture and how "cleanly" they burn, a higher BTU rating means a higher power output and also a better MPG rating, gasoline's BTU rating has been steadily decreasing as more and more low BTU fillers are added


Race gasoline is made in much smaller batches and has a higher BTU rating as well as octane rating, thus the significantly higher cost, thats the performance gain you are seeing, not from the octane level itself though

 

Only the best for my VQ35DE; that only happens to be 91 in California though

.

 

91 over here too unless I add a little 101 from time to time when it is very hot. Boost + 110 summer day = bad.

 

Well then what is the chemical name for technron that you can buy for cleaning carbon deposits? My understanding from the tests we performed was the detergents levels were higher in the "premium" fuels from Chevron with whatever that CT44 or chemical name for techron was. Again this is my results I found from the tests we performed. Also would you say that time of year winter / summer blend, could potentially affect the detergent levels?

Yes on paper - again this is what I've personally seen from my years of driving + my dad who has driven 1mil miles+. I don't want to fill up premium in a low compression engine although spending $4 isn't that much (.20 *20) comparing costs of premium to regular especially if you are spending $$s for an expensive car. My saying has always been don't buy the car if you refuse to buy the gas. But the bigger issue is why the sudden raises in the price of gas, while the cost of a barrel hasn't gone up that much - refineries are at what 85% pre-Katrina?

I've always considered BTU the heat output of something, which obviously a higher amount means a better burn - however - in the instance of a grill - you add more burners to create a higher BTU grill - so throwing in more gas should increase the heat output. My thing is we should focus on making the gas engine efficient - and not worry so much about performance right now at least (can always throw on turbo / SC later).

Well thats racing fuel - but pre-combustion in very very high compression engines does occur, which makes more sense for a lower BTU in a higher octane engine.

 

good post. don't why so many people think premium gas has cleaning additives.

 

Ok so then are all additives created equal? Is there an advantage to using Chevron gas versus Shell?

https://shop.sae.org/technical/papers/2000-01-2020

 

yes, additive between companies are different, but the the amount used in each grade is the same

 

It's all I've ever tried to provide Colin.

 

Well then you need a lesson in civility and common sense, because you certainly don't come across that way. I thought that was obvious to you, Jeff.

Stay tuned. You are the topic of conversation with the admins and mods right now!

C.