clmulli

Saw this article. What's your take?

http://moneyland.time.com/2011/08/19...mium-gasoline/

SRPE350

Interesting pitch - I tend to think buying/leasing a better car would improve performance and should run better. BTW - I usually fill up with midgrade (89 octane)..

listerone

Before owning my Benz and BMW I owned two Infinitis.The owner's manual of both *recommended* Premium but specifically said that it wasn't *required* and that use of 87 grade gas would cause the car no harm but *would* result in reduced performance.IIRC,the owner's manual of my W212 specifically *requires* premium.Given that we're talking $60K cars and $4 per tankful why take the chance?????

EmE247

Think you get more milage with the higher octane too besides any performance gains... and its "required" by MB.

What trips me out is you can be in one city and see premium gas at under $4.00 and be in another city 10 miles away with premium going for over $5.00 on the same day...

Interesting read tho... There's one about aftermarket car warranties that should prob be posted in the AMG forums...

Gsc

Premium does give better performance and mileage, but with gas being high, the car will be fine with regular.

I would always put regular in my 750il and old s500 with no issues.

Arrie

My two cents...

Any modern car can run any octane fuel that is sold for use in cars. Some cars "require" high octane, some do not.

There is a truth to the "folklore" that higher octane fuel gives more performance and fuel mileage as so many peiople say or think. It is true for cars that are made to operate with high octane fuel, like most foreign cars are, like the MBs and Toyotas.

With octane rating fuel can be made to tolerate more compression without self detonation. Higher compression gives more "kick" from the burning.

A lot of folks fill up with low octane fuel even when the car is optimized for best performance using high octane, but this does not save any money. The gas mileagte goes down and for that it turns out to be very close to a flush compared to more expensive high octane but what you definitely loose is with pewrformance. It is very easy to feel how 87 in the tank is weak compared to 93.

I don't understand why MB "requires" high octane fuel as their cars run fine with lower octane too. Their engines are equipped with knock sensors just like everyone else are. But, as it does not make sense to use lower octane why would anybody do that?

My 2011 E350 goes 26+ MPG with 78 MPH highway speed running on 93 octane. When it drops down to 24 MPG I know the fuel in my tank is not 93 octane even when that is what I filled in at a pump. But the engine runs just fine with some loss of performance.

BudC

Good response. It makes no sense to me to pay upwards of $60K for a car and then try to save a couple of bucks on fuel. I can say from experience that when I went from using 91 octane fuel with ethanol in Minnesota to 93 octane Shell in another state, my 300E would perform noticeably better and the fuel mileage would improve by at least 2 MPG.

I now live in Arizona where it can get pretty hot. I've noticed cars knocking after they've filled up with regular grade fuel.

K-A

That's an interesting point. I notice when I leave CA to go to NV, I get better MPG, whereas when I leave NV to go to CA (putting in "91" every time), I get about 2-3 MPG less. Not surprisingly, maybe it's because I'm not actually getting "91" in NV (considering how drastically terrible the economy and financial situation of most residents there is, it's no surprise that nobody probably selects 91, so it loses octane whilst sitting there).

Either way, stop being cheap people. If it says it "requires" it, then why take the chance. Find ways to skimp out elsewhere.

hyperion667

seriously! stop being cheap.......it's a only a few cents!

220S

My take? Time Magazine is a POS rag that distills articles from other sources to make stupid lists that hopefully will sell their publications.

Has anybody actually read the original C&D article? It's not at all what Time's 'Moneyland' (a useless copy filler section) said.

Time says this: "Car and Driver magazine conducted an extensive study and found that for all but the most high-performance cars, putting high-test into your tank burns nothing but cash."

But C&D actually said this as their conclusion: "Our tests confirm that for most cars there is no compelling reason to buy more expensive fuel than the factory recommends, as any performance gain realized will surely be far less than the percentage hike in price. Cheapskates burning regular in cars designed to run on premium fuel can expect to trim performance by about the same percent they save at the pump. If the car is sufficiently new and sophisticated, it may not suffer any ill effects, but all such skinflints should be ready to switch back to premium at the first sign of knock or other drivability woes."

Read the article. And anyway, it's an article from 2001 that Time just now decided is "news."
http://www.caranddriver.com/features...emium_-feature

btw, can we finally quit with these regular versus premium threads? And quit posting from these "Bud Light" sort of sources.

El Cid

Not an issue anymore. Michelle Bachmann was in S.C. this week and said if elected, gas will be less than $2.00 per gal. BTW, it is about $3.40 for regular in SC due to very low gas tax and no sales tax.
Does anyone know why premium should sell for 40-50 cents more than regular? About five years ago, it was only 20 cents difference.
Regardless of price, I always use premium.

Arrie

There we have it. And my post is strictly based on my own experience. Never saw or read any article about it and it all makes perfect sense if you understand how the engine works.

hyperion667

guys buying regular: try saving the latte money from all week and you'll have saved enough to get premium instead........or whatever the beverage......

K-A

I'd like to hear her thoughts on exactly how this will be possible.

.... Actually, no I don't, but I'd like to know if those who are paying attention, know if she has given a rationale way for this to happen, or is it simply the worlds-biggest cheap-shot to get the American commoner to vote for her.

listerone

If Osama Obama's despicable drilling bans were lifted,his promise to bankrupt this country's coal industry was recinded and his trust-funded tree worshiping donors were to shut up about "fraking" the price of oil would drop by at least $30/barrel overnight thanks to the psychological effect alone.Perhaps that's what Bachman has in mind.


As for the price differences Premium runs about 25 cents/gallon more than Regular where I spend most of my time.

WEBSRFR

GREAT! Who opened this can of worms? Now it is open season for all the bigots to come out of the woodwork to spew out their hateful political drivel.

With how polarized our country and politics are right now 1/3 of the country thinks the other 1/3 is insane and completely nuts and the 1/3 in the middle is disgusted with the other 2/3 and think they are insane and completely nuts to so fervently support one imperfect ideology over the other.

So could we PLEASE keep politics out of a CAR forum? There are enough other places to spew our political garbage all over the place.

Realize the forum membership is more or less a cross section of the population so when you make a political statement you are likely going to offend and invite retribution from those who oppose your ideology and turn off the rest of the people in the middle who are sick of the two imperfect political ideologies that have come to represent the politics in this country. Not to mention non-Americans who probably care even less.

Please let's stick to what we all love... cars! Safe driving to all no matter where you stand politically and may the patron saint of ball joints and Aireseus (the Airmatic god) be with you!

hyperion667

I think the OP opened the worms....but I think that was one damn good statement
websurfer, rock on man!

bigben320e

Amen and excellent point. Let's leave race and politics out of a discussion which is beaten tired more than a spent out 60 year old has been **** star.

Mercedes require premium gas. It says it on the manual, the gas cap, websites, and when you talk to your dealer SA/SM or indie tech they will tell you that and explain why. If you need an explanation why they need premium gas or have a desire to use regular/mid-grade perhaps you should:

1. Not have a Mercedes to begin with, if you cheap out on gas you will falter on care of the vehicle altogether. If you cannot afford a few cents more on every fill-up how can you afford brakes? filters? oil change? GET A CHEAPER CAR that does NOT require premium gas.

2. Bing, Google, or STFF on WHY these cars should use premium gas, but again if you are asking this question, refer to #1 above.

We need to stop answering and creating these types of threads, they make no sense and do not add value at this point. Just a suggestion...

K-A

WELL SAID!!!!

I'm sick of Political BS all over the place. You know what both "sides" have in common? They both suck!!

Over it. Now back to the cars.

samkimg

Yes, back to the cars +1

Here in NorCal, Premium 91 is usually just a dime over the mid-range 89 and 20 cents over the regular 87.

evanswan

there is tons of science on this and break down on political reasons for gas hikes. Lets get some good info together to figure this stuff out.

e15 mixture set by the goverment to offset useing actaula oil. So why are fuel prices rising?

It's like cutting your drugs. I want pure gasoline, not some watered down crap. they are screwing us.

http://www.msnbc.msn.com/id/39653350...asoline-tanks/


Where the Automakers Stand
Automakers have repeatedly expressed concern about the effects of E15 on engines and fuel-system components, particularly for smaller vehicles such as lawn equipment, boats and motorcycles. In May, the industry organization Auto Alliance issued a statement urging the EPA to delay a decision on the E15 waiver until all testing is complete. The auto industry has spent $6 million of its own money to test E15, and won't be done with testing until 2011. On Sept. 21, the Auto Alliance wrote a letter to the EPA reaffirming its concerns about E15, stating "a ruling without completed testing is not supported by our members."


The Government Mandate for Renewable Fuel
A Renewable Fuel Standard set in 2007 by the Energy Independence and Security Act requires that 36 billion gallons of alternative fuel such as ethanol be incorporated into markets by 2022. According to the DOE, about 11 billion gallons of ethanol were used in the U.S. in 2009. Most of that comes from the existing supply of E10 dispensed at most gas stations today. That market is hitting a wall, so without a transition to E15, it will be difficult to stay on track with the Renewable Fuel Standard requirement.

Read more: E15 and the EPA - Is E15 Ethanol Safe for Cars? - Popular Mechanics

El Cid

If you really want to do something about ethanol, contact both your US Senators and your US Representative - and do it now.
However, the Agri-business conglomerates, "farmers" organizations, ttransportation industry and politicians are firmly entrenched in supporting ethanol.
Not because it lowers demand for foreign oil (which it doesn't), but because it makes millions upon millions of dollars for those involved in it.
Not just "farmers", but ethanol processing companies, rail and truck transportation companies, local distributors (AKA tank farms), ad infinitum.
There are two components to this welfare program. One is the requirement for ethanol in gas and then the 45 cents per gal. subsidy for making it. Then you can all the other agriculture and business tax breaks along the line.

ghh429

I've had to lecture MB master techs about how Bosch, etc. advanced engine management systems work because even today (although its getting better) there seems to be real misunderstanding about how important octane is for engine performance.

As some background - in the eyes of an OEM car maker all higher end car makers try to extract as much performance out of the car as possible because HP rating is important for bottom line sales. They typically design a car based on 93-94 octane which is available throughout the developed world then they bring the car to California for testing on 91 octane Summer Formulation because everyone knows this is garbage gas. During these tests they will typically "dial back" the existing tune to accommodate for crap cali gas. So you guys with Cali cars are already running a "dialed back" map assuming the OEM choose to provide different maps for different regions - if not then 91 octane (if recommended) typically is the MINIMUM THRESHOLD to meet the OEM's engine designs.

Adaptive Engine Management:

Now modern engine computers have all sorts of closed loop feedback systems that measure for gas quality. Generally this relies mostly on knock detection (a microphone) and 02 sensor feedback. When you put crap gas into your car you end up detonating - the car pulls timing, richens up the fuel mixture among other things. This protects the engine when you get a bad tank of gas. The problem is that most EMS have a time table for this - so if you're on a long trip, cruising at 20% throttle at constant speed on 87 octane the computer gets "happier and happier". It starts running more and more aggressive maps. Then all of a sudden you give it a lot more gas (say 70% throttle) under increased load and boom you're detonating. Worse yet say you are running an aggressive map and you go 100% WOT where the car shifts into open loop (high RPM and high exhaust flow operation is typically very hard to measure for detonation and afr targets so many EMS do not do it) and you are detonating like crazy. This detonation is causing damage to your pistons, piston rings, rod bushing, etc. etc. A few bad detonations or even a few thousand small detonations won't take out an engine just like how your wheels won't break if I take a hammer to a few times. But what about if I take a hammer to it a thousand times? A hundred thousand times? I think you get the picture. If the OEM is saying 91 octane is required and you live in Cali and it's the summer - I suggest you run it.

Cheers