I’ve herd htat the difference in gasoline grade is mainly in the octane but other things are added (or subtrated) too.
Is there anyone out there who can give a more knowlegable input on this?
Hey guys! I own a 2001 VW Beetle Turbo 5-speed. When I bought it new, the salesman told me I had to run premium in it because it was a “performance engine.” It’s the same engine that’s in the Audi TT sports car.
Well, after about a year, one of the dealer mechanics told me I did NOT have to run premium in it! In fact, several mechanics told me the Turbo Beetle would run just fine on mid-grade. I made the switch, and the Beetle has run fine with it. I have 146-thousand miles on it, and it still runs and looks like its brand new!
Gary
Hey Dave! I have the same experience with my 04 RX-8. The performance seems the same, but the mpg goes way down. I tried regular when I was on vacation and premium was unavailable at the gas station I used to fill up, and my mpg dropped to 22-24 mpg on the highway. Usually the highway mpg is almost 30.
I have used premium gas in my cars since I bought a new Corvette in 1971 and the owners manual said to use regular gas in it. My father who was a mechanic scolded me for doing such a thing and ordered me to use premium gas in it. I do believe premium gas does two things. One, it maximizes horsepower of the engine and therefore its performance. More importantly I believe that premium gas helps keep fuel injectors clean. In driving three new cars over 250,000 miles I have never had a problem with the fuel injection systems in them. Maybe I am just lucky…lol. This is just my humble opinion and it is worth what everyone is paying for it…nothing…lol.
i had a 96 chevy z71. i kept a log of every fill up which included odometer/tripometer reading/miles between fill ups (which I filled up at every visit to the pump)/brand/premium level/and cost per fill up and whether or not I used some additive. There were times when I actually got better mpg with the cheap stuff. Otherwise, there was no significant difference in the mpg between the premiums for the 5 years I had the truck. Now if you want to talk about $$ per mile, well then that's a different result!!Are you guys actually this clueless as to how cars work?? Your show is great entertainment to me, but sometimes I am in total shock in the level of your ignorance of how an engine runs and what it needs. I remember a comment in a show a year or so ago referring to VW’s and oil viscosity. The callers had an oil light which was coming ono and were told it was caused by using 5w30 or 10w30 oil, when it should have had 20w50. Ya’ll said no cars take 20w50 unless the engine is worn out and your trying to keep from burning oil. WRONG ANSWER. ALL GERMAN CARS USE 20W50 MOTOR OIL up until the mid 90’s!!! Where do ya’ll come up with some of this crap you spew out??? Sometimes I think if you ever had any mechanical training, it must have been 40 years ago, and ya’ll have never read another book since. Time to get some update educating guys. But fuel octane is not new school knowledge. So now I wonder if you have EVER read a mechanic training book, or if 100% of your knowledge is shade tree work?? Do or did ya’ll really run your own shop? This is really basic stuff!!
ALL GERMAN CARS USE 20W50 MOTOR OIL up until the mid 90’s
Well my 1970 VW 111 did not use 20W50. I don’t even know if 20W50 was available back then.
I’m happy to see that somebody else knows that dollars count too.
I go with Joe. I have NEVER seen #50 oil recommended for ANY car. I know many people use it, but no car manufacturer ever recommended that it be used. That stuff is for worn-out trucks in the summer time.
Now, back to “Octane” Do you know how Octane is determined?? With a single cylinder laboratory test engine built specifically for this purpose. These engines have adjustable compression ratios, carefully calibrated. An unknown octane fuel is run in the engine and the compression is increased until it starts knocking. The spark advance and RPM is FIXED at a set number. Only the compression ratio is changed. In other words, it is the compression ratio that determines the octane number, not detergent level, not BTU content, but only compression ratio. So if you have a car engine that runs fine on 87 octane gasoline, you are wasting your money feeding it 92 octane gasoline. More information. Five octane points are not that many. Engines that need 92 octane to run completely knock free, will run pretty good on 87 octane…They might experience slight detonation, but not destructive detonation. Back in the old days, “regular” was 90 octane and “premium” was 100+ octane, a TEN point spread. If you put regular in your Super-88 Olds with 10.6 to 1 compression, you sure would get some spark knock, but even then, it would seldom if ever would harm the engine…But it would get your attention. Most of todays drivers don’t know what spark knock and detonation is. The have never experienced it…
The octane requirement of an engine is a function of the compression ratio and the shape of the combustion chamber which determines the flame pattern and travel. If the manual calls for premium, put premium in the tank. Remember 60s musclecars with sky high compression ratios of almost 12:1? Those cars needed the very best fuel. On the other hand, a car can be right on the line for regular, such as my 1980 Olds 88 350V8. This car would run on regular at lower altitudes, but required premium at higher altitudes, such as Colorado. In such a situation, go to premium. One oil company in this region put premium in both storage tanks at their stations to cut down on the complaints, since many cars experienced ping on regular. An other reason for needing a higher octane occurs whem your engine carbons up due to poor maintenance. So there is no conspiracy; if you want to save money buy a car that does not need premium.
about the oil question;in the book"how to keep you’r voltswagon alive for the compleat idioit",the viscosity issue was addressed…
the “idiot’s” book states thatthe air cooled engine was desined to use S.A.E 30 in the winter,andS.A.E. 40 in the summer,or during heavy use…
using ANY kind of multi-grade oil was a recipie for disaster in a engine where the oil was the coolant,as well as the lubricant-as was proved by a friend’s -64…my friend found this 64 in this old guy’s back yard,with the origional 1300cc engine!.spent 2 grand having it rebuilt,religusly changed the oil with mobil 1(5w30)
it lasted almost two years-then siezed the crankshaft at the #4 journal,sending the rod through the block…fortunately,l.a. had a ton of them around! found a used ENGINE for $200.,poped it in,started running straight sae 30,was still running when he sold it!
…as for premium vs reg,…i’m now back in ohio,found a -92 aerostar(ford) for cheap,lying dead in this woman’s driveway…it started and idled,but would die when you tried to accelerate-even in netral!
she had been running cheap gas in it(a 4.0) in overdrive up and down the hills in cincinnati…it took me two months of changing fuel pumps,having a garage tell me it was the timing chain(i took it apart,chain was fine-despite 150.00 on the odomoter)
.tom and ray will get a kick out of this!!
…this thing had “preturbed” me to the point of primitive weapontry!..while noticing how quiet this thing idled,i went to the tailpipe and listened…then it ocured to me!..the catalytic converter was plugged up so bad that it wasn’t letting the engine breathe!..maybe “beverly hills cop” was in there somewhere,but i thought of THE BANNA IN THE TAILPIPE theory!
ran a coat hanger up the pipe-just to eliminate that as a possibility…then,out of shear frustration,was trying to knock a hole in the converter before spending $400.for new converters on a car i paid $200.for,the framing hammer knocked the blockage loose!!
HALELUIA!! i tried to start it again.a huge cloud of black crap came out of the tailpipe,and this little ford ran like a champ!!!
…i’ve been driving it now for three years,with a rescue mission to florida when my brother in law’s truck blew up in chicago…
…i’ve got to type quietly,as when i start bragging about my cars,that’s when they break on me…i kick the rusty fenders,laugh as some more of it flakes off ,call it a rusty old hooptie,start it up,and go where i need to!
…being that it was nearly killed by econo-gas,i try to run the good stuff…maybe i’m lucky,as the marathon near me has “super thursday” where mid grade and premium are the same price.it gets better mileage with the better grade,and with the goods in the tank,it has yet to fail to start,despite spending a week sitting in the parking lot,at sub-zero temps we had last winter,or record heat this summer…
.with it’s mileage,it starts getting fussy starting and accelerating. while putting premium in a old truck like mine,it seems to wear less on things like fuel pumps and injectors.it’s now pushing 200.000 and(fingers crossed) it’s still running!now watch! it’s gonna leave me on foot real soon now,-cause i was bragging on it…OH,WELL, life can get that way!
…fellas,i listen when i can,and the show both entertain’s AND informs!keep up the good work!you are providing a service for all us people who may never graduate any farther,than to drive other people’s throw away cars!
Tom and Ray often speak of “miracle in a can” products. That’s where “miracle goo” comes from.
Sea Foam is a good product when used for its intended purpose, cleaning deposits in combustion chambers and injectors. A 12 ounce can @ $6 will treat an entire tank of gas adequately, but you don’t need to do it very often. Twice a year should be sufficient with modern fuels which have their own additives. You DO need to run premium in your Mini Cooper if you expect it to last as long as a BMW should.
As for cleaning you injector and carburetor, please note you have four injectors and NO carb.
Discussions about premium vs. regular gas seem to ALWAYS be confined to the octane argument. And that’s probably the most important consideration. But there are others: Marketers of premium gas want you to sincerely feel that your car runs better on the stuff, and “running better” entails things other than spark knock and/or power and economy loss due to ECM retarded timing. There’s a fuel parameter called “RVP” (Reid Vapor Pressure). It’s supposed to be varied by geographical area and climate and is a measurement of the volatility of the fuel. “Volatility” does NOT mean how “explosive” the stuff is; rather, the ease with which the stuff is vaporized. And it significantly affects cold and hot starting, idle stability, and overall running of the engine. Whatever it takes to achieve this, they put an absolute minimum of it in regular gas, but are much more generous with it in premium. Additionally, federal law now requires minimum quantities of detergents and intake valve cleansers and, whatever that minimum is is what you get with regular. Premium has more of it and it’s of higher quality. Most of my engines were designed for regular, but I occasionally run a tank of premium through each one of them. It seems to allow them to run better than if I run bottles of injection cleaner through them. And under severe conditions I use premium gas. By this I mean pulling a 10,000# trailer up steep hills on 95 degree days, etc. This way I know I can stick it right to the floor in any gear and hold it there without blowing holes in the pistons, which is exactly what would happen if allowed to ping under heavy load. And since the RVP is much better controlled the fuel isn’t going to boil in the line as it passes across the top of the engine (which it occasionally does in spite of the presence of a vapor return line). Every engine is different, even if they were built consecutively on the same production line. And knock sensors and ECMs are all a bit different, too. Their calibrations can’t be held exactly the same. And everyone drives and uses their vehicles a bit differently. What this says is that the only way you’ll know if premium is better for you is to try some of it. You may be impressed while the guy next door, with a car “identical” to yours, isn’t. I’ve also heard that, while midgrade is blended from tanks of regular and premium in the ground at your local station, and is usually priced halfway between regular and premium, it is actually comprised of about 2/3 regular and 1/3 premium. This could come about if actual octane measurements are not linear functions of fuel volumes. So for all you octane fans, that’s something else to try to save a little money; buy half regular and half premium and see if it runs better than it does on midgrade. I’ve also found that my '93 Corvette runs great on regular IF I also throw in a pint of “99% isopropyl rubbing alcohol” with each fill-up. Ethanol does NOT have the same effect; isopropyl must have a greater octane enhancing effect. Do NOT try this with other than PURE alky as others are mixes of alky and water. A pint of this stuff is available around here at health and beauty departments for about $1.19. When they go on sale for 69 cents I buy a dozen of 'em. Anyway, my point is that there ARE other considerations in how your car runs besides the octane of the gas. The oil companies all know what these are and formulate their fuels to try to get you to perceive that your engine’s OVERALL operation is better. Whether it’s worth the extra money or not is a judgement you’ll have to make for yourself.
My dad told me that you have to use regular (87 octane) for 4-cyliner, midgrade (89 octane) for V6, and premium (91 octane) for V8 and higher cylinder engines. The Lincoln Town Car I currently own (1986 model) has a 5.0L V8 engine; when regular fuel was filled the engine knocked pinged thus requring a higher octane, usually premium to help it run smoother. I have a 2008 Toyota Highlander & a 1989 Toyota Camry and both have a V6 engine, both of these cars recommend a midgrade (89 octane) for excellent fuel economy even though regular gasoline is required.
From my viewpoint, even thought your owner’s manual states you should use Regular & stick with it, unless your vehicle has a V6 or V8 engine which could benefit power & economy with a higher octane.
Using lower octane in an engine DESIGNED FOR 91 will cause not only loss of power, but will also result in carbonization, as well as causing actual mechanical damage.
If there is no detectable detonation, there is no “need” for premium fuel. But if it makes you feel better using it, hey, step up to the pump! The oil companies are counting on you feeling that way…
I don’t claim to know much about either gasoline or gasoline engines much less how they retard or advance timing. I do know that in Pennsylvania, the gov’t mandates a different blend of gasoline from June through September. I also know that under a heavy load during “summer fuel” season, using 87 octane in my '05 Yukon Denali (I know it’s a gas hog…) heavy pinging ensues and my mileage drops quite a bit. A simple upgrade to midgrade prevents the heavy pinging although in extremely hot weather it still pings a little bit. What’s more, using 87 octane, the power drops off dramatically using summer fuel but during the winter 87 works fine. I also own a '05 Subaru Outback with an H6 engine and without premium fuel (it’s premium “recommended”), summer or winter when you need acceleration like on one of our famous Pennsylvania 50 foot acceleration ramps, the car falls flat on it’s face. I mean, afraid you’re gonna get rear-ended falls on it’s face. Not mild hesitation but pump the gas pedal three times and then maybe it’ll take off. I’m pretty sure that’s a subaru flaw but it’s easily solved by greasing the palms of the oil companies.
Quite simple answer for me:
Eighty-eight octane for the 2001 New Beetle turbo, 91 for the beloved 1974 Superbeetle convert (103-octane racing fuel is too pricey).
Michael
The car will be running less ignition advance, so it’s reasonable to assume that EGTs will be higher. It probably wouldn’t be high enough to damage the turbo all on it’s own, however, the pre-catalyst found in the exhaust will start to break up with higher EGTs. In turn, the turbo will now be getting a plentiful supply of ceramic catalyst through the exhaust turbine.
Also, the car will pull timing if you run poor fuel but it takes time and it only responds to something going wrong. This is why many motorsports tuners don’t develop calibrations with a knock sensor, because by the time you get meaningful data from the sensor you’ve already put the motor under stress.
Ok I was not careful in what I wrote. Try this: I don’t believe that the cars specifying premium only have the retard timing feature designed to handle regular without possible damage to the engine.