claude
Expert Class
Posts: 205
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posted August 26, 2003 04:19 AM
Premium vs regular gas question
I don't want to discuss the power advantage of using or not premium vs regular gas. Here, my question is: does premium gas have more additives into it that help to minimize carbon deposits on intake valves?
I'm asking because many years ago, when I was driving a VW Jetta, the only gas that VW was recommending was Ultramar's premium because of its additives. By then, VW cylinderheads were easily carbonised and the aforementionned was the only one that was passing a certain "BMW test". Since that day, I have been using only premium gas everywhere (motorcycle, car, lawnmower, etc...). But now, with the ever rising selling price, I'm thinking to swith back to regular which is about $0.08 less a liter. What is the 2003 situation about additives in premium vs regular? Thanks!
  
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phukit
Novice Class
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posted August 26, 2003 04:55 AM
Higher octane fuel takes longer to ignite, which resists pining and detonation. The manual calls for minimum 90 then that's what I run because if not you risk damaging the motor. Usually the higher the compression ratio the higher octane is needed.
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2002ZX12R
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claude
Expert Class
Posts: 205
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posted August 26, 2003 05:22 AM
quote:
Higher octane fuel takes longer to ignite, which resists pining and detonation. The manual calls for minimum 90 then that's what I run because if not you risk damaging the motor. Usually the higher the compression ratio the higher octane is needed.
phukit, I already know about all this; my question is about something else. Thanks anyway.
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ScaredyCat
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posted August 26, 2003 06:44 AM
I think it's more to do with the detergents added rather than the octane - different manufacturers add different stuff. You'd have to find out which ones are designed to keep your intake valves clean - lots of the manufacturers add stuff to do this. It's not based on octane (premium, regular, super or whatever).
By the way, my 03 says a minimum of "95+ octane" on the tank....
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TurboBlew
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posted August 26, 2003 08:31 AM
I dont think Premium would "burn" any cleaner than 87 or 89 octane gas.
But then again... what do I know?
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RAC4IT
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Bergie
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posted August 26, 2003 08:39 AM
Running 89 will show a power improvement and will leave less deposits on your valves.
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frEEk
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posted August 26, 2003 11:01 AM
higher grade gas, which inevitably means higher octane, does have more additives, including detergents. every grade of gas has the additives, just differing amounts of it. this is true of octane, which is added via an additive, and all teh rest of it. for some chains they also oxygenate the higer grades more, which should actually mean better power (this is only true of chevron as far as i know), but whether that power increase is balanced out or even outweighed by the loss in power from running too high octane, i dont know. the real question re detergents and how clean they keep ur engine, is again which factors prevail? as rac4it mentions, lower octane will burn better (this is by design) hence it _shoudl_ burn more complete=cleaner. but the higher grade has more detergents, which should also make for a cleaner engine. dont know which one wins out tho. my take is use the octane level/grade ur vehicle recommends. any gas is gonna have enough detergents to keep ur engine reasonably clean, and running more octance does nothing but improve your 1/4 mile times by lightening your wallet.
re the ultramar recommended by VW... first off i'd ask who exactly recommended it. the manufacturer themselves? or the dealer? i'd only trust the former. and in that case, it would be because they had a particular problem with their engine design that their recommended fuel compensated for with their particular additive. either that or they were paid to recommend it. who knows.
scaredycat... that would be the RON octane number. normally octane is published as RON+MON/2, a formula u have no doubt seen on pumps and vehicles many times. RON tends to be a higher number than MON. RON of 95 is the same as pump rating (PON?) of 91, or premium. here's a good brief description of the issue: http://www.btinternet.com/~madmole/Reference/RONMONPON.html
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Y2KZX12R
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posted August 26, 2003 12:45 PM
Yes, from what I've read the top grades of fuel from whomever have better additives to reduce carbon buildup in fuel injectors and the back sides of the intake valves.
As far as it having any effect on reducing carbon in the combustion chambers I havent seen that claim.
Remember, all pump gasoline is the same when its made and it all goes into a sharing system that pumps it thru pipelines all over the country all mixed up from one refinery and the next. Its made to an agreed standard by EVERYONE!
What makes the fuel unique is when its pumped from the storage tanks into the trucks. Its at that point that the various manufacturers/distributors add thier "special" additive packages to customize the fuel and call it thier own.
You wont see a power loss using a fuel that is just a few points higher in octane rating. Say 93 vs 91 or 94 vs 91. We've tested a dozen fuels on a mule engine with corrected A/F ratios and saw more of a hp difference in who's fuel is was rather than what octane rating thy CLAIMED it had.
Now, if you ran lets say, 110 mon+ron/2 octane rated race fuel in the zx12r you might see a power loss. But even then its more of an issue of what fuel you are talking about. Theres plenty of 100+ octane rated fuels that will out perform 89-94 pump fuels. But its not because of the octane rating.
3 years ago exxon had a 92 octane oxy fuel that was great on the dyno. They sence changed the formula and its not any better than any other anymore.
Another thing to remember, in the northeast and other high polution areas the fuel additives are different than lets say, kansas.
Also winter gasoline is mixed different than during the summer.
One thing we never did was test summer vs winter fuels of the same brands. But where the hell do you stop?
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frEEk
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posted August 26, 2003 12:58 PM
yeah, good point on the season and geographical differences. different mix in Vancouver compared to Whistler (where i used to live). 2000ft elevation difference and slightly different climate meant they adjusted the fuel a touch. in winter, they add antifreeze too.
oh, one other point i fergot to mention. at Shell (i used to work at a station), they actually only have regular (bronze) and premium (gold) gas in the tanks. their midgrade (silver) gas is jsut a 50/50 mix of the 2, mixed right at the pump at delivery time.
as with all the stuff i'v written, this may differ from company to company and liekly from canada to the US too. again, most of my info comes from Shell canada since i worked there for a few years.
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zx11_12
Expert Class
Posts: 207
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posted August 26, 2003 01:24 PM
I work for Marathon in the gasoline laboratory. You guys are right, higher octane does have more detergent /anti-oxidation/anti-corossion additives.
Also, higher octane doesn't burn slower, it resists pre-ignition better than lower octane gasoline. The speed of the burn is determined by a whole mess of factors, density, atomization, combustion chamber design, even the specific "recipe" of that gasoline.
What most people don't realize is that gasoline isn't made like oh..say Pepsi...a specific recipe every time. Gasoline, by definition is a hydrocarbon blend that has a boiling point below ~460 degrees F. Federal and state regualtions limit it more by specifying varpor pressure, distillation specs, etc. However, any blend of hydrocarbons that can meet these specs is considered gasoline. At our refinery, not even any two blends of the same grade are made exactly alike. It all depends on the crude oil we're using, the varying inventories and prices of the various components and more. So two different batches of the same octane from the same refinery will burn differently because of the different blend of components. It's too simplifiied to say that one grade burns slower than another.
That said, some brands/grades are more consistent than others. I know some who claim that Amaco 93 makes more power. I can't verify that, but I do know that Amaco specifies thier 93 octane gasoline to be clear (not yellow) which is much harder to make and therefore limits the variety of recipes you can use and still get it right. So it stands to reason that thier gasoline would be a more consistent blend.
That's probably more than you wanted to know about gasoline.
Steve
OH, BTW, almost all staions have only a premium and a regular tank. Mid-grade is mixed at the pump.
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jonwright
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posted August 26, 2003 01:26 PM
WOW! Nope - this kind of stuff is just what we want to read! Thanks!
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frEEk
Administrator
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posted August 26, 2003 02:07 PM
damn zx11_12, i need someone like u to clear up the "straight talk about dynos" thread!  good info, thanks.
i'm confused about one thing tho. how does what u said about different recipes and Amaco calling for specific specs correlate with what Y2K said about all gas bein mixed together fomr all refineries? is the final stage of refining what makes the difference?
also, re mixin of grades, what about 4 grade stations (87/98/91/94)? i was todl that when the station i worked at was gonna get 94 (still hasnt happened several years later) it woudl be a separate tank. 87/89/91 would continue to be a mix between 87 & 91
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Y2KZX12R
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posted August 26, 2003 02:46 PM
 Edited By: Y2KZX12R on 26 Aug 2003 15:52
http://www.nacsonline.com/images/pr_toolkit/prtkdistribution_lg.gif
So Joe calls Sam and says i need some spec. bla bla bla and they pump it to them. From what I've read they dont even use "pigs" anymore to divide the different base stocks.
They pump fuel for a lenght of time and then switch to another on the fly. Some mixes and that stuff is sent to a holding tank and reproccessed.
There is quite a lot of info on the topic if you really wanted to read.
Gas here is now 185 for the 87 cheep stuff. I guess with the power outage the whole system got screwed up.
Super is over $2 a gallon.
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Zx23rr
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Mahogany Bomber Pilot
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posted August 26, 2003 03:34 PM
while where at it, there is some advantage in tuning an engine to a fuel. To assume that if you change the gas in the tank from one brand to the next, and you get more or less power, there is a reason. Mostly fuel distillation curves for one. You will find that the "race fuels" has a curve that starts "boiling off" at as cool as 91 F. And could have 90% by volume boiled off by as low as 265-294 F. This will make very good power if you don't have problems like startablity. And the A/F will have to be therefore adjusted as "more" fuel will be available to combine with the oxygen (note I did not say air). Or put another way, less fuel will have to be put into the combustion chamber as most of it will vapouries when compared to Pump Gas. BTW, Pump gas distillation curves are something like first 10% at 130-140 F and 90% as high as 475-495 F.
Does this make sense?
Claude, To answer your question, traditionally, the higher the octane, the more additives, the "cleaner" it (supposed) to burn. NOT necessarily Better!
But once the vavles get carbon loading on them, then performance suffers. But most of that stuff comes from oil getting by the valve seals. If you ever have your valves out, polish the surface to a shine. Makes it harder for the carbon to stick.
my brain hurts now....
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frEEk
Administrator
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posted August 26, 2003 04:05 PM
damn, the west is pretty barren on the map eh?
we just went to 91.9 cents per liter for regular here. gettin out of hand.
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auszx12r
Parking Attendant
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posted August 26, 2003 08:34 PM
I know this isn't really related to the initial question but I can get my hands on regularly racing fuel, 100octane is it worth it, I think it will cost me about 1.15 per litre is it worth it? and will it do any damage in short or long term to a 2000 12 with kn, arkapovic pipe and Pc 3r. Should I get the bike mapped again to suit this fuel?
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your car is slow
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posted August 26, 2003 08:54 PM
On this note...I took a gander at putting a gallon or two of 89 in the tank (vs the regular 93 I use)....Perhaps its just me being optimistic...but the bike feels like it is making more power....to me it was a noticeable difference.
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VincentHill
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posted August 27, 2003 01:00 PM
I ran Chevron in my wife's 911S mostly because Shell caused it to vaper lock with the high engine compartment temps! WHen I took the engine apart, the intake valves were totally clean and where the fuel entered the combustion chamber, the piston was clean down to the metal! My understanding is "ALL" Grades have the additives, but since this cost money, I would feel that the additives would be less in the cheaper fuels! Techron is used by Porsche dealers to clean the engine and remember, Shell sponsers Porsche!
BTW, the Exhaust Valve had 1 inch in diameter deposits! I had to use a round file to clean the exhaust valves. You cannot believe how much better an engine runs with clean exhaust valves!
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Hells Dark Lord
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posted August 27, 2003 01:15 PM
I was down in Jacksonville the other day was gonna holler at Kevin, but I didnt realize that the shop was closed on Sunday, or maybe I didnt realize it was sunday...anyway......was running low on cash so I opted for the 89 instead of the 92 octane gas....will NEVER do that again....bike ran like do do all the way home.....didnt think about the ignition being advanced when I put it in.....am sure that was the hardest 120 miles on my motor yet....
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frEEk
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posted August 27, 2003 01:47 PM
yeah, witht the advanced ignition i dont think i would be goin to less than the recommended 91. u may be gettin into knocking zone there. undoubtedly this is only a concern under certain loads/conditions. now in the case of CARS... since they often (always?) have knock sensors these days, u can put pretty much ANY octane level in tehm & they'll run fine without damaging the engine. u will get less power, but realistically this isnt a concern 98% of the time. this was from the mouth of some big wig (VP or something) from GM, so i'd tend to think it can be trusted. no knock sensors on our bikes tho. wish we had em.
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TurboBlew
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posted August 27, 2003 02:46 PM
quote:
I know this isn't really related to the initial question but I can get my hands on regularly racing fuel, 100octane is it worth it, I think it will cost me about 1.15 per litre is it worth it? and will it do any damage in short or long term to a 2000 12 with kn, arkapovic pipe and Pc 3r. Should I get the bike mapped again to suit this fuel?
I wouldnt see using 100 octane unless you bumped up the compression some. On a stock more 92 works good.
You'd do better to use oxygenated fuels like Nutec.
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Zx23rr
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posted August 27, 2003 03:54 PM
food for thought, if you are running Ethanol blended fuel, one would think to get back some of the power, the A/F ratio would have to be richened up accordingly. This would increase hp, but fuel consumption would increase as well.
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necro
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posted August 27, 2003 04:27 PM
I'd better stay out of this "long post" thread 
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necro
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posted August 27, 2003 04:27 PM
I also better stay out of it because I don't know much about gas
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Y2KZX12R
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posted August 27, 2003 08:09 PM
Edited By: Y2KZX12R on 27 Aug 2003 21:14
Yea I guess in theory you would want to add fuel to the map for any fuel that had ethanol in it. Alcohol engines require ALOT more fuel than gasoline engines. I forget now but its about twice the burn rate.
So for your street car you would want a fuel tank holding about 30-40 galons of methanol to go the same distance as 20 gallons of gasoline, all other things being equal that is.
I could find out what the methanol consumption rate is per hp if someone was really in need of that info. My buddy has had methanol engines on the dyno and it gives you fuel comsumption rate data on the pulls.
Good point on the knock sensor freek. Its all part of a closed loop real time system. The new honda might just have this system. The only reason we dont see it on bikes more is gotta be cost I would think. Althou the cost of these sensors has come down quite a bit over 20 years, a pizo quarts knock sensor is costly. And thats just one of the several extra sensors needed to have a true closed loop system.
This may sound crazy but if the feds cracked down more on federal emitions laws on bikes we might just see these systems on every bike. Not because they would want to but because they would have to to meet the standards. But because of the HD crowd and AMA lobby you wont see it for some time if ever. A HD would have a hard time passing 2004 car emitions standards. Even with a catalyist. Dont get me going on those junks.
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