Part of the performance you will be sacrificing is gas mileage.
Don’t waste your money
I use regular in my VW turbo,drink the cheapest no-name scotch, brush with Chinese cut rate toothpaste after eating Mad Cow steaks, I even pass up Shubert concerts for Car Talk and even married the homeliest girl in school. I look forward to my cutrate pre-paid dumpster funeral which has resulted from use of my low cost HMO
Moderator, censor, or whomever you are, just because I disagree with Tom and Ray about the basic premise of their question isn’t adequate reason for you to cut my statements out of the board. Are you afraid of a difference of opinion? If this cannot be an open place for discussion, it may as well be shut down.
Now that’s funny.
My 2007 Lexus specifies 91 octane. When I absentmindedly put in a FULL tank of regular the car ran terribly & got 15% lower mileage.
When using 91 or 94 octane with 10% ethanol the car ran fine but got 15% lower mileage, so I stay away from Sunoco gas.
O.K. A short prmer on fuel octane and spark advance. Octane is gasolines rating for resisting combustion, the higher the octane the more you can increase both the compression ratio and the timing advance, without detonation or pre-ignition (ie. engine ping or knock).
Modern car igniton systems sense “knock” with a special sensor and adjust the timing accordingly, if the enngine is a hi-compression variant it will “knock” at a lower timing advance point than a lower compession engine. If an owners manual reccomends premium or hi-octane fuel it is because that engine is a hi-compression variant and will knock too soon in the timing advance curve, the engine control unit will sense the knock and retard the timing. This results in lower performance and reduced fuel economy. (You may try a simple test on your own late model car by using premium for a couple of weeks, the gas mileage should improve. It may not improve enough to warrant the added expense of the higher octane fuel, however.) So, for the people that have bought late model, perfomance oriented vehicles it is alwalys wiser to use the reccomended octane rating, IF, they want all the power and performance they spent their hard earned money on, when puchasing such a vehicle. Technoid
I"m not entirely sure where ‘miracle goo’ came from, or what made you think it’d cost me more than buying 91, or even why it would cause my warranty to be invalid. But it’s called Sea Foam, and it cleans out my injecter and carburetor, lubricates my upper cylinders, removes moisture and stabilizes my fuel. It cost me about 6 bucks and you only need to use one ounce per gallon. Even if i used 91, using this product still wouldn’t be a bad idea. I’m preventing wear and tear ahead of time.
I want to throw in a wrench in your discussion. I live in California and we have three grades of octane. We have the low 87, medium 89 and of course, 91. I always use 87 in my '98 Camry 4 cyl. Would going up one grade change anything in performance or mileage?
Even the premium in my area does not fit the bill…so to speak…unless I give my 99’ Porsche Boxster a drink of 104 Octane Boost it feels like I am pulling a trailer…can’t imagine what would happen if I tried 87 ???
My wife’s 2000 Avalon V-6 runs pretty well on reg or premium. Checking mileage in W. Texas’ level ground via running about 200 miles, refilling and calculating mileage (not using the computer display), reveals
mileage on regular @ steady 75 mph gives 26.1 mpg. Premium gives 28.6. I guess that is because of the high-tech engine. Anyway, if the difference in price is 20? or less, it is cheaper per mile to run on premium. More than 20? difference, reg. is cheaper.
I bought a used Pontiac Grand Prix GTP with a supercharger. I noticed after I bought it that there was a lot of carbon on the tail pipe flutes. Two weeks after getting it I also noticed a sign on the gas filler cap that said “Use premium gas only”. I started using Premium, and noticed better performance, and no more carbon. I assumed that the carbon build up was from the car’s computer trying to conpensate for the low octane gas. Was I way off base here?
another consideration, is that you pay the SAME TAX on each gallon, regardless of grade.
so proportionately, there is less tax on premium than regular.
I just wonder if putting 101 octane in my chevelle would be better or worse than 93.
I agree that Premium is the way to go. In my 94 Jaguar XJ 12 it has 11 to 1 compression and I wouldn’t try regular if you paid me! In my 88 Jaguar XJ 40 I tried regular in it once wow what a difference. It went from not slow to slug. I had to add 4 bottles of Lucas to the gas to get it up and going again! If it says premium only they mean it! In my 82 F-250 with 465k on the clock I even run mid grade.
I have an old (83) high compression motorcycle and premium is needed, but…
Now that I know premium is being diluted (enrgy/volume) I’d like a list of ethenol content of various vendors so that I have a better understanding of the fuel I’m buying. Anyone have a link to that info?
Several years ago I completed a “body off” restoration of a 1953 MGTD. The effort included a complete rebuild of the engine and carbs. The engine rebuild included replacing the cam with a Moss “high performance” cam. Following the restoration I experienced frequent periods when the engine would lose power and “knock” excessively. All the experts I spoke with were mystified. The problem was exascerbrated when I drove home the 60 miles from a car show in San Juan Bautista, California, (where my car had won 1st in class). I had filled the car with regular just before departing. Any time I got over 45 it would pull the loss of power trick, a very embarrassing situation on 101. In desperation, I drained the tank upon my return and refilled with premium. The car has run perfectly ever since! All my “experts” question this because the engine has a low compression ratio, but, what the hey, it works. Any comments?
After replacing the fuel pump on my 1996 Cadillac STS, my great mechanic told me that ethanol tends to “eat” the components of fuel pumps in GM vehicles. I have since stopped purchasing gas products that have ethanol and started using Premium.
Someone correct me if I’m wrong, but for the past few years the Govt. (EPA) has ordered that all fuel sold in the U.S. must contain a min or max (I forget which) of 10% Ethanol.
If I’m right then how are you going to get away from ethanol and if your in Minnesota(?) perhaps you should have bought a car with an engine that runs on straight ethanol.
Sounds like a bunch of BS to me; either the mechanic is misinformed or lining you up to for more repairs that won’t be covered under warranty or GM is trying to find excuses for poor fuel pumps.
I’m the original owner of a 1989 Chevy Full Size Blazer w/ a 350/5.7 w/ 160k mi on the drivetrain with nothing but EXTREMELY regular tune ups and fluid changes (It’s my baby, what can I say).
For years I would regularly fill (approx 30 gal.) my tank with Premium fuel just for the “additional additives”, whether it truly cleaned anything; I doubt it, but it was done before going on a 300mi one way usually non-stop drive. That alone should have cleaned anything up, regarless of what fuel I used. I did notice that when I used Premium my engine would run a little smoother and my MPG was increased ever so slightly, not anywhere enough to cause me to buy Premium, it definetly would not have been cost effective. Oddly enough throttle response was a little better but power was less, again small differeces nothing great. I definetly wouldn’t tow with Premium, complete waste of time and money.
I read somewhere and discussed with a mechanic years ago an interesting issue with the computer in my truck. I doubt this has anything to do with any newer (OBD II) computers or even GM today but it was specific to my computer and for the time. Maybe someone out there knows. The way I remember and understand this is that the computer has a set of default parameters to run the engine in, if something unusual were to occur like poor fuel or minor malfunction of a sensor the computer will accomodate for the event but still try to run the engine as per the default parameters which, depending on the situation; may sometimes cause short hunting periods; especially on start up. If this condition continues for 500mi the computer will then keep these new values as it’s standard and it won’t hunt anymore. I did notice that when I used Premium fuel, in a way it seemed like my engine didn’t know what to do with it at first. The catch to this is that when you reset the computer, such as when you disconnect the battery or if the battery dies, the computer goes back to the default parameters and has to learn the new ones all over again. This also goes for error codes where if the computer doesn’t see a recurrence of the code for 500mi it deletes it.
I lived in NYC and when it was found that the additive we used in our fuel was deemed enviromentally unsafe, the EPA ordered that all fuel must use a 10% ethanol additive. Well, when that happened I noticed an immediate change in the power of all 4 of my vehicles and of course the controversies began. What I soon later learned after tring to weed out fact from fiction was that the ethanol actually reduced efficiency by about 15% so that means not only are we paying more for gas (mostly through taxes) but we’re also paying extra for them just to add the additive. So now, we need to fill up more frequently than if we were using straight gas, that explains my power reduction. I would like to know by what percentage is there an emmissions reduction by using ethanol. I have a feeling that a tank full of fuel may give off less emmissions but not really when you have to burn more fuel to get the same result as non ethanol, then therefore giving off more emmissions in the long run.
As mentioned here by Car Talk; “the major companies add ethanol to increase octane”. Alot of people think of octane equaling power and that is a misconception. Previously I mentioned how there’s a 15% decrease in efficiency due to 10% ethanol. Well, Octane actually refers to the amount of anti-knock compounds or property the fuel has not its power giving ability, this property causes the fuel to burn a little slower and therefore more controlled. The result is 87 Octane actually burns hotter and faster than 94 Octane. This slower burn is why we should use it in high compression engines which are more readily apt to knock on a fuel that burns quicker giving all of it’s power in one quick shot; slower burn = more control. Anyone who understand ballistics should also understand this, basically the same rules apply; bullet weights, powders, barrel length, it’s pretty much the same concept. You may ask, then why do we use high octane in racing, bottom line slower burn = more control. If you can truly harness and control something more easily; then you can squeeze out, harness and make more use of the power that is released. Remember the internal combustion engine is super inefficient, I forget the numbers but only a very small amount of the power is released to your wheels; most is lost in the form of heat,gas and friction. Using Premium fuel doesn’t automatically cause you to use it more efficiently, your engine must be tuned or designed to use that fuel. If your car says use 87 octane; use it, your not getting any benefit by using anything higher unless your engine is pinging. The gas stations love us for our ignorance, most cars on the road are designed for 87 octane, it’s only a small percentage that ask for Premium and the oil companies want you to think different. Who really knows more about your car, the manufacturer or Big Oil?
One more thing; Car enthusiasts can be really sensitive about their cars. We love them as if they were our children but, sometimes that mixed with some pre-conceived ideas or misinformation, we interpret what is happening with our cars incorrectly; especially novices or newbees to the car lovers culture. I don’t truly know for sure but an issue of 87 octane in a modern high compression engine shouldn’t have much effect unless the computers parameters are so tight that it doesn’t allow for it, I just doubt it since fuel at the pump actually varies. The sticker 94 octane only means that the fuel will contain an octane of no more than 94 octane, we don’t actually know what we’re getting. The gas stations also don’t have actual pumps anymore they are actually called blending units, where tanks of different fuels are then “blended at the pump” to give you (supposedly) the octane that you want. Read or listen to the advertisments when they mention “their blended fuels” that is exactly what they truly mean, rather misleading but effective advertising. This varying octane and there is info somewhere that has stated that the octane variance isn’t tight at all but can swing widely. This in mind I just find it hard to believe that these cars run so poorly on 87. If anything it may be an issue (maybe) such as the one with my blazer that it may take a while for the computer to truly adjust to the new fuel and it may be more noticeable on a 4 cyl engine since you have less cylinders (than an 8 or 6) to spread out this dificiency or have the others to smooth it out.
In the past years of leaded gas, carbon build-up was a problem. Plugs and oil also needed to be changed more often and engines didn’t go much past 100K miles. Today regular and premium gas no lead and better detergents so carbon build-up is much less.