Premium gas? Not in my Ford! Or my Lexus, or my Mercedes...

Ford Motor Co., which currently sells one trim level of one model that requires premium fuel, is now bragging in a press releases that not one of the cars and trucks in its 2009 lineup (except that one trim level car) will require premium fuel.

That's right, a car maker that essentially does not make and has not made something is pleased to announce and that it will continue not making that thing, all in the name of saving its drivers cash. From the release:

With per-gallon prices hovering around $4, customers are sensitive to every penny spent at the pump, and Ford Motor Company is leveraging technologies to help consumers avoid an even further hit to their wallets. Ford, Lincoln and Mercury vehicles, including luxury models like the all-new 2009 Lincoln MKS, run -- and run well -- on regular unleaded gas, a true competitive advantage given today's skyrocketing fuel costs.

Whether this is news or just some half-baked piece of public relations spin is beyond this forum's scope. But it does raise the endlessly debated topic of whether most cars, including high-end, $80,000 European luxury machines, actually need the high-test fuel that their user manuals so strenuously recommend.

The number of cars requiring or recommending premium has exploded in recent years. According to Kelley Blue Book, fully 279 current-year model trim levels fall in those categories, or 14% of all trim models for all models of cars available. That's up by two-thirds from 2002, when 167 cars and trucks, or 7% of the total industry fleet, called for the pricey petrol. That's a startling increase, especially since the underlying technology involved -- the internal combustion engine -- hasn't changed that much in the last six years.

The issue here is knocking, which is what happens when some of the gasoline in a cylinder ignites at the wrong time. That's more likely to happen in engines that run hotter or have higher engine compression. And due to some complicated issues involving organic chemistry, the higher the octane rating, the less likely that is to happen.

As Ford points out in its release, the only car it makes that can't run on regular unleaded is its Shelby GT500, which has an engine with a supercharger that can increase temperature and compression. The reason that Ford's fleet can run on the cheap (OK, not quite as ungodly expensive) stuff is essentially because its engines don't run that hot, don't have turbochargers or superchargers or don't have particularly high compression.

Is that the case for other car makers? Few can agree on this. Mercedes makes 38 vehicles for which premium gasoline is recommended. That turns out to be every model Mercedes sells, according to a spokesperson. And Eric Noble, president of auto consultancy the Car Lab, says that "there are no false premium fuel stickers on gas caps," arguing that with gas at $4 plus, car makers would prefer to advertise their cars as Ford has: cheaper to run.

Defenders of the 92 octane juice claim it boosts performance. Indeed, Ford claims that it adds five horses and four foot pounds of torque to its new Lincoln MKS sedan.

Yet according to an article in Scientific American, most cars don't need anything more than the 87 octanes delivered by regular gas, and a few years ago, a spokesman for Porsche admitted that the fancy German cars, all of which come with recommendations to use premium fuel, "will run on regular fuel without damaging the engine." Some critics even suggest that car makers use a premium recommendation (rather than a premium requirement) as a kind of status add-on, making the car seem fancier.

The debate may rage, but consumers are voting with their wallets. With the spread between regular and premium widening to as much as 40 cents lately, sales of premium have been tumbling, down to about 8% of the market according to data from the U.S. Energy Information Administration, from 16% in 1997. And with 35.6 million gallons of premium fuel sold a day, 2007 was the worst year for premium since 1983.

-- Ken Bensinger

Photo: Karen Bleier / AFP/Getty Images

Comments

[David S]

I have run my Subaru Outback 2.5 XT Turbo on 87 octane since it was new (104,000 miles) with no knocking or other problems whatsoever.(Subaru recommends premium fuel)

[Dan]

My Miata said "Premium Preferred" on it. I found it got about 3 MPG more on premium thn regular, thus making the extra cost worth it. However, on a normal car, rated for regular, premium gas does nothing at all for it.

[PERRYinLA]

I have the same experience as Dan- if premium is recommended, it is best to use it since you will get better MPG, more than paying for itself. Porsche's admission that their cars will run on regular fuel without damaging the engine is not the end of the story- anyone doing so in their Porsche will not get as many MPG.

All cars that take premium fuel have sensors that detect if you use regular gas, retarding the timing and ensuring you don't damage the engine, but, again- your MPG will suffer.

[aram]

My motorcycle recommends 95 octane. 91 or 92 seems cheap in comparison, to say nothing of being easier to find. What I have not heard answered is if people who drive in the higher portion of the rev band ought to stick to the "good" stuff.

[Mark]

I'm wondering what Ford's soon to arrive "EcoBoost" engines will run on. Anyone know?

[chad]

I used to drive a Volkswagen Jetta VR6 that required 91 gas, at least according to VW and the service guys that I talked to. I was told that you could drive it on 87 if that's all that was available but you shouldn't for an extended time. The service guy said to only get enough 87 to get to a gas station that sold 91. Whether it's that dire of a situation I don't know since I got a lot of bad advice, bad service, and generally a bad car from VW.

I drove it for 6 years and found the entire time that the price differential between 87, 89, and 91 was always about 10 cents/gallon per grade and it seems to still be the case. (87 to 89 was 10 cents extra and from 89 to 91 was another 10 cents.)

Obviously people are paying attention to gas prices more now but they still aren't paying any more extra for 89 or 91 than they were before.

[Sal Cangelosi]

Replying to aram's question: Ford's new "eco-boost" technology will run on regular unleaded.

[Sal Cangelosi]

Replying to aram's question: Ford's new "eco-boost" technology will run on regular unleaded.

[Robert]

"What I have not heard answered is if people who drive in the higher portion of the rev band ought to stick to the "good" stuff."

Actually detonation (knock) is more likely at higher loads and _lower_ rpm. Detonation has less time to develop at higher rpm and with smaller cylinders.

For your motorcycle, check what kind of octane number they mean. There are 3 common octane measurments: "Research", which applies to light loads, "Motor" which applies to heavier loads - this is the useful number, since knock at heavy loads can damage an engine in short order - and "Pump", which is an average of the two. Gas rated at 95 RON would be around 92 PON, so you'd see 92 on the pump.

[Robert]

It's almost funny how much misinformation is published in newspapers regarding how to take care of one's car, fuel economy and related issues. The topic is seen more as filler or an attention getter rather than serious news which would require fact checking (they do check the facts in the main news section, right?).

Anyway... there's no "debate" on this topic.

If you are not concerned with the last detail about your car, simply use the fuel reccomended in the owner's manual. That's it, no fuss.

If you want to save the last nickel or do absolutely the right thing for your car, read below.

In most cases, the small savings from running regular in a "Premium Reccomended" vehicle will be lost with a small drop in fuel economy, *and* you'll lose some amount of power with no offsetting benefit. *Some* fuels have a better additive package in premium than regular, but an easier way to get the best additives is to check toptiergas.com. Worry about that only if you have an expensive engine or if top tier is reccomended by the mfr.

You could test to see whether you're in the minority that can drop back to regular, saving 5-8% per gallon without losing about that % in mpg. *But* it's hard to test small variances in economy in normal driving, since weather, traffic, and your own driving vary the results a few percent anyway. Plus it's difficult to fill the tank to exactly the same point every time.

You can get a clue though; find out what the difference in power rating from regular to premium is. If the difference is less then 3-4%, there's a good chance you can run regular without an efficiency loss. You'll never feel 3% in hp or torque, nor will it hurt the engine. In the MKS mentioned above, Ford reccomends regular despite a trivial gain from premium. In short ... Ford's reccomendation was correct to begin with.

If your car has a turbo- or supercharger and is reccomended for premium, you'll lose quite noticable power on regular. You're also depending on the knock sensor to save the engine, sort of like volunteering to get shot while wearing a bullet resistant vest.

If you tow a trailer or drive in 100F+ tempuratures, you'd be wise to use the reccomended fuel without fail. Detonation is much more likely and the ECUs ability to protect your engine from below grade fuel is taxed.

The above applies to new cars or those in fine shape and average operating conditions. After 100K mi, you may need fuel a grade or 2 higher.

[Steve Colton]

Robert posts are really good, and he hit it almost completely right-on. However, I think a lot of people will have a hard time understanding the nuances: each engine, drivetrain, and vehicle set-up has peculiar operating characteristics. Some will be happy on lower grade fuels and some won't under VARYING "conditions." And there are numerous variables that come into play every time someone sticks the key into the ignition switch, including every driver and his/her inputs at that moment.

Here is a case in point: a '96 Maxima with manual transmission and 205k. According to the "book" it needs 91+ octane, but will run on 87 without damage, while suffering some performance loss. Indeed! While it has a fairly torquey V6 (meaning it has good pulling power @ low RPM) it has a relatively light flywheel and tends to stall more often from stop given the same driver and techniques. Some 87 octane also occasionally causes the inherently overly sensitive "knock" sensor to initiate a "check engine" condition through the computer controlling the engine running parameters. This is no fun to see on the dashboard, and unless you have your own tool to read, diagnose and clear the light it is an expensive annoyance. At 89 octane and using careful moderate operating manners the car runs smoother, rarely ever stalls, gets 5-15% better miliage, and the check engine light never comes on. Little to no noticable improvement is found at 91+ octane. This information may/may not translate to the identical vehicle with an automatic transmission, or the same car with a different driver, or the same car and driver at a different altitude, etc.

There is one underlying rule: do not use lower octane than that which causes preignition under 99% of your driving. And it is that type of general rule that leads to car makers recommendations for all of the varying conditions they cannot control.

One thing not mentioned is that the octane numbers on the pump reflect the MINIMUM that the gas coming out of the nozzle must meet by law. But, it could be higher. This can happen especially at independent stations for a variety of reasons. For marketing purposes you are unlikely to see mid-grade gas labeled 89+, though it might be. Bottom line is: stick to the car maker's labels, unless you're capable of detecting when preignition is affecting your car's performance. Then you can experiment. But, if your car has any version of OBD II, and you play with octane ratings in your tank, AND you hear knocking you're way over the line, or your car's self protective system isn't working properly. Either one of the above is bad. If you don't yet know what all of the above information means, don't try lowering your car's octane ratings until you do begin to understand.

[David]

I own a manual 2003 VW Jetta 1.8T (184hp Turbocharged Engine) and only 87 octane.

I push it pretty hard, 6-7000rpm and 90-95mph on a weekly basis and have yet to notice any "knocking" or "pinging". My driving style is definitely not "fuel conscious" but I still average 26-28mpg on mostly highway usage. It would be interesting to run 92 for a few weeks and see if the increased mpg offsets the cost, but I think the majority of people using 92 octane these days wouldn't notice any difference in their cars performance if you secretly switched them to 89.

[Garey G. Ris]

BMW had a news release recently saying that while premium is recommended, its engines will operate properly with only a slight loss in performance. Only recently have I begun putting regular fuel in my 2002 BMW 325i, with no noticeable performance issues. In Canada, premium sells for 40 cents/U.S. gallon higher than regular. Like other posters, I try to put Top Tier fuels in my car.

http://www.toptiergas.com/deposit_control.html

Click the tab to find Top Tier retailers.

As for mileage, by driving slower, I'm getting better highway MPG than the EPA ratings suggest.

[Nedly Mandingo]

Knocking can damage an engine because knocking and pinging are actually explosions inside your engine use cheap gas in a performance car and blow something your gonna foot the bill. Most high end cars lexus infiniti benz all use premium gas, it is actually quite easy to see why if you learn about engines and compression.

[Judas Gutenberg]

Back when I was living with my parents and driving a beat up 1970 Volkswagen Beetle (circa 1996), any surplus money was earmarked for gallon bottles of Carlo Rossi Paisano. I certainly didn't have any extra for gas, though it only cost $130/gallon in those days. Still, I found my car ran much cooler over Afton Mountain if I used the 92 octane, so in the end it was cheaper (I burned less oil) if I used the good stuff, even if it meant less red wine for me and my gutterpunk homies.

[Lana]

I drive a 2006 Mini Cooper which, I'm told, may void my warrantee if I do not use Top Tier 91 octane gas. Since I plan on keeping the car as long as possible and I drive it hard I find it very worthwhile to invest in Chevron 91 octane gas! I've paid as much as $4.89 a gallon. Luckliy my car gets great gas mileage.

[jgc711]

have a '96 integra gsr with over 120,000 miles...just to play it safe, i followed the manufacturer's recommendation to use premium only...never had any major problems with the car (knock on wood)...if a person could afford a porsche or a bmw or a benz, i'm sure the price difference between regular unleaded and premium unleaded would not matter...

[Bill]

Your older cars that run hot also require premium. One has to remember that gas stations used to sell 103 octane gasoline. Premium is currently a miserable 92 octane.

I have a custom engine in my Baja Bug and I not only have to fill it with premium, but add octane boost.

[SimpleComplex]

I've been told that the issue of lower octane "burning" by engines is predicated on a few sensors that are what the engine management systems use to adjust the compressions accordingly to lower the risk of pinging and its damage to engine parts. So in the end, the difference will be if the user will spend any $$ on replacing these sensors more frequently or spend more on gas that doesn't require the engine to recalibrate the compression at which it allows gas to ignite. That's from what I understand, though I'm not a mechanic so I can't substantiate it except that it makes sense to me. Hmm...

[John D.]

Relative to the price of gas, the additional cost of premium (20 cents a gallon) is not all that onerous. I have a car that requires premium. But my previous car, an Acura Integra, ran more smoothly with premium, so I always used the expensive stuff, even though the car would run fine with regular.

[CalvinL]

I'm from GB and my father owns a new BMW 525i, the petrol here is amazingly expensive!

It is about £1.12 per litre of unleaded fuel which is about $2.21! So a whole tank costs about £70 or $138.67!

[NV]

so let me see if this makes sense:
1. you've just sent your $1,000 check on your monthly lease for a MB/BMW/Lexus/Porsche, and now you are concerned about the extra $5 per fill up.
2. you've spent many $$$ on your aftermarket wheels, GPS, sound system, or any other upgrades, and now you are concerned about the extra $5 per fill up.
3. you've traded in your gas guzzler Explorer for a brand new MKS because that's what everybody else in the neighborhood did, at a loss of more then $5,000, and now you are concerned about the extra $5 per fill up.
I just love it, I absolutely do !!!!

[Chance]

I own a BMW 3 series that claims it needs premium gas. It runs a *little* different on the cheap stuff (little less power), but it runs just fine.

There are sensors in the engine that detect the firing rate of the gas it's exploding. If the sensor detects the cheap stuff, it alters the firing patterns accordingly. Thusly, it doesn't matter what gas you put in the car, the engine will adjust.

Beyond even that, these German cars are calibrated to fire off EUROPEAN premium gas, which has a higher actual octane rating than American fuel, so no matter what you put in it, the sensor is going to have to activate and adjust.

[Beidler]

THE FACTS:
All newer fuel injected cars are equiped with engine management systems that will adjust to the different fuel grades.

If you have forced induction via turbocharger, supercharger(blower) or nitrous, you MUST user higher octane. Not only will this maximize the HP and Torque output but it will help reduce denotation\knocking that is not always heard by our ears which will DESTROY your motor.

[Frank G]

Everyone seems to miss the following point. When you purchase a car and the EPA estimates says 25 mpg in a car that reqires premium gas, then you will not get 25 mpg if you use regular gas in that car. If you purchase a car and the EPA estimates says 25 mpg in a car that reqires regular gas then you will get 25 mpg if you use regular gas in that car. Therefore you are mcuh better off buying a Ford than a VW with a Turbo or an an Escape vs. a Nissan Murano or any other car that can use regular gas vs. one that requires it.

High end car companies can pump up thier mileage claims by "recomending" premium gas.