Gas regular or premium???

[QuantumRift]

There's just one flaw with this analysis. 100% of the BTU's in fuel do not go into moving the car forward. Much of that energy is lost to heat, overcoming friction, etc.

][/quote] Yes, I'm aware of engine...engine efficiency in the Physics.org forums..

 

[sandy]

Yes, I'm aware of engine 'efficiency'. I know thermodynamics well as in a previous career I worked for GE at the aircraft engine plant in Evandale OH as an engineer for compressors, combustors, and turbines.

Modern engines are pretty efficient. Of course 100% of the BTUs in a gallon of fuel do not go into moving the car forward. However, all things being equal, you can draw a very good general conclusion of what happens when fuels are blended. Closer tolerances, better lubricants, etc all contribute to better efficiency. Tires that have less rolling resistance, better wheel bearings, all contribute to overall efficiency (as does the transmission) of the system (car).

Again, as an example, I said if you have 10 gallons of pure gasoline, and that takes you 500 miles, your fuel efficiency is 50 miles per gallon. I don't really care about the 'losses' to heat, overcoming friction, etc. The fact is if I have 10 gallons of fuel that takes me 500 miles, then I've distilled the problem past the heat and friction factors. So yes, I and say that the BTUS in that gallon of fuel have taken me down the road as the "overhead" of producing heat and overcoming friction have already been met.

If I have 10 gallons of fuel and have expended it to move my car 500 miles, then I have expended 1.14 million BTUS of energy to go that distance. So what if some of it was spent overcoming friction or producing excess heat, or overcoming the rolling resistance of the tires. If I reduce the amount of pure gasoline in that 10 gallons by 10 percent, I still have to produce heat, I still have to pump oil and overcome the rolling resistance of the same 4 tires. SO that then has LESS BTUs and I travel shorter distance.

I ride a Suzuki motorcycle. If I burn E10 in it, my mileage does not drop 10%. The mileage decrease (not accounting for COLD/freezing weather) amounts to about 4.5% or so. Which works out, since I have a 4 gallon tank, when I replace it with E10, I have 3.6 gallons of pure gas mixed with .4 gallon of ethanol. The available BTUS are less, so I drive a bit less on a full thank. Changes in my riding habits and fuel are very readily apparent and recordable over a short period of time.

And if you look at 10 gallons of pure gasoline compared to 10 gallons of E85, it holds up well:

1 gal pure gas has approximately 1,140,000 BTU by volume.
1 gal of ethanol has approximately 76,000 BTU by volume.

Blend it to E85, and for example, you have 10 gallons of E85.

In that, you have 1.5 gal of pure gasoline = 171,000 BTU.
8.5 gal of ethanol equals approximately 646,000 BTU.

Add them and you have 817,000 BTU. By comparison, 10 gallons of pure gasoline has approximately 1,140,000 BTU.

Simple math shows us that, in this example, E85 has about 72% the available BTUS by VOLUME of pure gasoline. SO that 10 gallons of fuel, instead of taking you 500 miles down the road, can only propel you 360 miles down the road. That's REALLY close to the E85 is about 25% less efficient than gasoline argument. In an E85 capable engine, because it does not change the compression ratio to compensate for the fuel. If you toss out the losses and just compare the end result, it holds. It really doesn't matter that you have loses in overcoming friction or heat - that's built into the 'cost' of doing business. If I burn 10 gallons of fuel to get me 500 miles, it doesn't matter that my engine is 35% efficient - the END result is that I STILL combust 10 gallons of fuel to go 500 miles, all else being equal. If I install a set new tires that have low-rolling resistance tire, my engine efficiency does not change, does it? But I can go 510 miles, so I have burned less fuel, or expended less BTUs in the fuel in my tank, to go that distance.

Now if we actually are able to use butanol instead of ethanol, we're back at relatively decent comparisons to gasoline - butanol is almost on par with gasoline in terms of BTUs by volume, and can be run in an unmodified engine. We should argue engine efficiency in the Physics.org forums..

Maybe because I worked in advertising, a b s field where there never was a "right" answer, I love reading this stuff. I (heart-sign) engineers.

 

[QuantumRift]

Maybe because I worked in advertising, a b s field where there never was a "right" answer, I love reading this stuff. I (heart-sign) engineers.

Hahahahaha....you one FUNNY GUY!!

 

[QuantumRift]

One of the worst contributors to water in the gas is the condensation from driving around (but mostly the car sitting around) with a 1/2 to 1/4 tank of gas most of the time. I think filling up more often does a lot to mitigate water in the tank.

Also staying completely away from SA and PDQ, whose gas is completely inconsistent in its quality and purity (and I don't mean puregas, as in corn-free). I have learned the hard way spending hundreds on cleaning up contaminated fuel systems. Kwik Trip is a great choice if you want really good, top-tier gas at less cost than the majors. Also, I've used their 89 octane (often priced same as regular) as an alternative to premium. None of this however, is as good for your car, I believe, as BP 93 or any top tier gas without corn.

This is another fallacy. Your tank doesn't mysteriously fill up with condensate from sitting around. Fuel systems in modern vehicles are SEALED. That is, the only time air can enter the system is when you have it open for fueling. The E10 fuel does a good job of removing any water in the gas tank. When your tank is empty, the head space is greater (that is, the volume of 'space' above the fuel). But it's not filled with humid air waiting to condense on the sides of the tank when the temp drops...that head space is pressurized with fuel vapor (that 'pssssssssst hiss when you open the fuel cap). When you open the fuel cap, the escaping pressure causes an outflow of vapor (which gets captured and recycled if you have uncircumcised fuel nozzles in your area). If you have the uncircumcised nozzles, well, you then seal the tank during the fueling process so very VERY little 'water vapor' has entered your tank. You might get a little more water vapor with a circumcised nozzle, but I doubt it. When your are pumping fuel into your tank, it's being agitated and that causes the fuel to evap, and in doing so, will drive out any air and water vapor in that air, out of your tank.

In the "olden days" when fuel systems were primitive and vented to ambient air, oft times on a cold winter morning people would try to start their cars only to realize they had fallen victim to the dreaded "fuel line freeze up" caused by water condensate in the tank of pure gasoline with virtually no alcohol additives to remove said water. Today, such things as 'vapor lock' (eliminated with fuel injection) and "feeeze up" (eliminated with additives and closed fuel systems) ARE a thing "of the past".

I'm from Central Ohio (54 yrs old) and remember the SOHIO gas station chain, and their commercials that always said: "You go, or SOHIO pays the tow" because they used an alcohol-based additive.

[ame="http://www.youtube.com/watch?v=lVOJ2RqNYzg"]Sohio Standard Oil Weather Commercial (1960s through 1990s) - YouTube[/ame]

 

[Blackwme]

Premium...play it safe. if we can afford a 40k-50k car then the additional cost for cleaner gas is..what, 10 cents more a gallon and the car holds 19 gallons..omg..thats an additional $1.90 per tank. cleaner gas= Cleaner fuel injectors, heads, pistons, and fuel system. No Brain-er!

 

[Jimmmmbo!]

Premium gas does not equal cleaner burning. It's just refined for higher octane.

Detergents can be added to any grade fuel, and unless specifically stated by the vendor regular has the same detergents as premium.

I think what you're supporting is actually Top Tier gasoline.

 

[Ernie3647]

http://bottomline.nbcnews.com/_news...f-ethanol-in-gasoline-as-corn-crop-wilts?lite

Less corn....maybe

 

[StangKiller]

premium without Corn if possible.

+1

 

[Potty_Pants]

Premium...play it safe. if we can afford a 40k-50k car then the additional cost for cleaner gas is..what, 10 cents more a gallon and the car holds 19 gallons..omg..thats an additional $1.90 per tank. cleaner gas= Cleaner fuel injectors, heads, pistons, and fuel system. No Brain-er!

Ive put premium in quite a few of my cars last 5 years with the bmw too. Ive driven a tankon premium vs regular in this car and didnt see any benefit... perhaps later, we'll see. For my area its .20 - .25 more for premium vs regular. Im happy with the additives the fuel companies put in their regular grade of gas. I cant justify spending $4 more per tank with no gains or better cleaning.

Put a tune on then ill run premium, but not now

Ppp

 

[jpierick]

I did the old test on one tank of regular gas and then one tank of premium gas. Both my wife and I could tell the difference in performance, we have a 5.0 with 8,000 mile on it. The pick up was not the same with the regular gas , so nothing but premium from now on we like the performance value that it gives us.

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[EXBMWGUY]

I did the old test on one tank of regular gas and then one tank of premium gas. Both my wife and I could tell the difference in performance, we have a 5.0 with 8,000 mile on it. The pick up was not the same with the regular gas , so nothing but premium from now on we like the performance value that it gives us.

I tend to agree that the performance is better with premium, especially the BP 93 that I try to purchase every few tankfuls.

I have seen a platinum R-Spec on Dodd Road near Lifetime Fitness in Lakeville. Is that your car?

 

[Midnightsun]

If 7 hp is noticeable to you on a 400+ hp engine because you use premium then you must have super powers. It is amazing what the mind can do but then again this is proven with the placebo effect. Betcha if they swapped to regular label with high octane you would still say the high octane performs better. Years back they advertised premium as having more power, the government intervened because this was false advertising and nothing has changed today. Premium fuel has no benefit whatsoever if your car was designed to run on regular. In the V8 Genesis we have a choice however the cost of premium vs the minor increase will never pay for itself nor will it help your engine in the long run. I know this is a classic argument and there are people who just cannot get past the word premium as not being better for the engine in general even though this is completely false.

 

[EXBMWGUY]

If 7 hp is noticeable to you on a 400+ hp engine because you use premium then you must have super powers. It is amazing what the mind can do but then again this is proven with the placebo effect. Betcha if they swapped to regular label with high octane you would still say the high octane performs better. Years back they advertised premium as having more power, the government intervened because this was false advertising and nothing has changed today. Premium fuel has no benefit whatsoever if your car was designed to run on regular. In the V8 Genesis we have a choice however the cost of premium vs the minor increase will never pay for itself nor will it help your engine in the long run. I know this is a classic argument and there are people who just cannot get past the word premium as not being better for the engine in general even though this is completely false.

How dare you mock my super powers!!

 

[Midnightsun]

How dare you mock my super powers!!

Sorry, did not notice your car was black. There is an exception on black cars which I forgot to mention and there is definitely a real world difference on those. Heck I tried to race a black Genny once but he killed me after a few feet.

 

[Mark_888]

Years back they advertised premium as having more power, the government intervened because this was false advertising and nothing has changed today.

Wrong. A lot has changed, and engine technology has changed significantly, especially the ability of an engine to use computer controlled variable timing, etc to take advantage of multiple different octane levels, depending on one's desire for cheaper gas with less octane, or higher octane for more power and better fuel economy.

The Hyundai Tau V8 has been specifically designed to use regular or premium (or obviously mid-grade) depending on whether wants the extra HP and/or better fuel economy. Whether or not the benefits outweigh the costs of the more expensive premium gas is another matter than only each individual can decide, but it is completely false to say that there is no difference or it is just a false marketing claim (at least in the case of the Tau V8).

"Years back," the choices were not available because engines were mechanically controlled and designed to run on one and only one octane level (although when cars got a lot older they sometimes needed additional octane to avoid detonation/pinging).

 

[jpierick]

EXBMWGUY, that is not me. I do live down by there, I drive a white 5.0 non R-Spec.

 

[EXBMWGUY]

Sorry, did not notice your car was black. There is an exception on black cars which I forgot to mention and there is definitely a real world difference on those. Heck I tried to race a black Genny once but he killed me after a few feet.

And I bet it was even hauling a boat!!

 

[EXBMWGUY]

EXBMWGUY, that is not me. I do live down by there, I drive a white 5.0 non R-Spec.

I'll wave if I see you!

 

[Midnightsun]

Wrong. A lot has changed, and engine technology has changed significantly, especially the ability of an engine to use computer controlled variable timing, etc to take advantage of multiple different octane levels, depending on one's desire for cheaper gas with less octane, or higher octane for more power and better fuel economy.

The Hyundai Tau V8 has been specifically designed to use regular or premium (or obviously mid-grade) depending on whether wants the extra HP and/or better fuel economy. Whether or not the benefits outweigh the costs of the more expensive premium gas is another matter than only each individual can decide, but it is completely false to say that there is no difference or it is just a false marketing claim (at least in the case of the Tau V8).

"Years back," the choices were not available because engines were mechanically controlled and designed to run on one and only one octane level (although when cars got a lot older they sometimes needed additional octane to avoid detonation/pinging).

Who said anything about cars not changing? Even a 12 years old knows that they in fact have changed substantially. What was said was regarding premium vs regular in power. Many people use premium in their regular recommended car because they were led to believe through false advertising there was a performance gain. This is what has not changed as there is no performance gain in this case. This is especially true in the V6 version of the Genny. As for the V8 it can use both however the hp gain which is undetectable costs 20 to 40 cents a gallon more. If you want to throw money out the window I have no problem with this as long as it's not my money. In fact I encourage you as they can make more profit and therefore keep the price of regular fuel down since the premium users are partially subsiding the regular prices.

Regardless here is some good info and this is not from a few people on a forum or blog somewhere. Important to note is regular or premium have about the same btu value or power if you prefer.

http://www.consumerenergycenter.org/transportation/consumer_tips/regular_vs_premium.html

http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-premium-g

 

[Mark_888]

Who said anything about cars not changing? Even a 12 years old knows that they in fact have changed substantially. What was said was regarding premium vs regular in power. Many people use premium in their regular recommended car because they were led to believe through false advertising there was a performance gain. This is what has not changed as there is no performance gain in this case. This is especially true in the V6 version of the Genny. As for the V8 it can use both however the hp gain which is undetectable costs 20 to 40 cents a gallon more. If you want to throw money out the window I have no problem with this as long as it's not my money. In fact I encourage you as they can make more profit and therefore keep the price of regular fuel down since the premium users are partially subsiding the regular prices.

Regardless here is some good info and this is not from a few people on a forum or blog somewhere. Important to note is regular or premium have about the same btu value or power if you prefer.

Using subjective evaluation terms such as "undetectable" is not helpful. The facts are that the certified HP for the 2013 Genesis 5.0 Tau V8 is that it delivers 421 HP @ 6400 RPM with regular fuel, and 429 HP @ 6400 RPM with premium fuel. Very similar differences exist for other Tau versions and model years. Those are the facts Jack. As I clearly stated, it is up to each person as to whether the extra HP is worth the extra cost of premium, but the extra HP is real.

The rest of you post is a mix of ancient mythology based on old engine designs and out-of-date consumer information, especially if the manufacturer specifically says it run on either fuel and gets more horsepower with premium.

If you want to argue that the increased HP is not worth the cost of premium fuel, that is fine, but please stick to the published HP numbers for each fuel. Personally, I do not think the extra horsepower is worth the extra cost, which is why I purchased a V6, but some people may think otherwise.