Premium gas vs. regular: What's really better for your car? (CBC Marketplace)

[RussianSensation]

[Exhibit #1] Premium gas vs. regular: What's really better for your car? (CBC Marketplace)

- Does Premium Fuel clean your car's engine/burn more cleanly for the environment?
- Does Premium Fuel improve your car's mileage?
https://www.youtube.com/watch?v=FPPkPAbzwbU





[Exhibit #2] "They tell you premium because they're trying to support advertised horsepower ratings," he told CNN Newsource. "But you won't harm your car at all putting in regular. Even Porsche's chief engineer says you can run your Porsche on regular gas."
http://articles.courant.com/2011-04...1_premium-gas-higher-octane-gas-expensive-gas





[Exhibit #3]
July 16, 2015 -- Edmunds: Save Money and Stop Buying Premium Gas

"Drivers used to buy a tank of premium gas every once in a while to clean their engine. Years ago, premium gasoline contained more detergents and additives to stop carbon deposits. But experts say that because of government regulations aimed at cutting emissions, all grades of gas, including those you buy at independent, low-price stations have plenty of additives to both protect engines and cut pollution.

Edmunds has compiled two lists: "premium recommended" and "premium required" for vehicles from the 2010-2015 model years (with some 2016 model-year vehicles). If your vehicle is on the "premium recommended" list, you're OK to try switching to regular unleaded gasoline. If, on the other hand, your car is on the "premium required" list, then you have to run premium fuel. You can confirm the information on these lists by checking your owner's manual.

It's a different story for a car whose engine requires premium fuel. The car will still run on regular fuel in a pinch, but you shouldn't make a habit out of it. The fuel's lower octane can result in elevated exhaust-gas temperatures and possible knocking, both of which can adversely affect the engine's health in the long run. Running regular-grade fuel in a car that requires premium might sound like a good way to shave a car's running costs, but the short-term savings won't come close to offsetting the cost of repairs to a damaged engine.

For those driving "recommended premium" cars, however, it's just a matter of driving moderately and avoiding acceleration with a wide-open throttle. Do that and you might never feel the difference between using premium and regular grade gasoline: and neither will your car."


Thoughts and any other scientific data that contradicts the above?

 

[jlee]

A modern car will have a knock sensor that'll pull timing in order to save the engine if you're running crappy fuel.

If you have a modded car tuned specifically for 93 and run 87 in it, you'd better hope your tuner set up knock detection properly or you are looking at a new engine build.

 

[crashtech]

Didn't watch the video. Modern vehicles have very fine control over fuel and spark delivery, and therefore are not only able to run on a wide variety of fuel qualities, but are able to do it at virtually any altitude and temperature as well. The only thing you lose by using fuel with lower octane than the engine "wants" for a particular set of circumstances is horsepower, since the engine management will pull timing and enrich mixtures to ensure detonation-free running at the expense of power.

 

[RussianSensation]

Didn't watch the video. Modern vehicles have very fine control over fuel and spark delivery, and therefore are not only able to run on a wide variety of fuel qualities, but are able to do it at virtually any altitude and temperature as well. The only thing you lose by using fuel with lower octane than the engine "wants" for a particular set of circumstances is horsepower, since the engine management will pull timing and enrich mixtures to ensure detonation-free running at the expense of power.

That's pretty much the conclusions from these articles from 3 different sources. The loss in horsepower in non-performance cars is not really important. If you have a Corvette ZR1/Z06 or Porsche 911 Turbo or BMW M3/M5/X6M, sure. I bet even the 2015 Mustang GT may only lose 10-15 HP with regular fuel. Unless you are going to the track or racing daily, I think it's not worth the premium for a car unless it requires it. Although, Edmunds did compile a list of vehicles that require premium fuel. I suppose if a vehicle requires premium fuel, then it's probably more reasonable to use premium but I clearly for most regular cars, buying mid-grade or premium fuel is a waste of $.

 

[shortylickens]

The problem isnt octane. the problem is that damn alcohol.

 

[crashtech]

Alcohol has high octane, which allows refiners to use ever lower octane gasoline when more ethanol is added. The more ethanol is added, the lower the BTU content of the fuel, and the lower the resultant MPG in computer controlled vehicles.

 

[tortillasoup]

great thread

 

[Art&Science]

This really only applies to new cars with 1.) Octane pins (which detects the grade of fuel and tells the computer which automatically adjusts spark and timing advance/retard) and 2.) Knock sensor(s) to prevent predetonation resulting in engine damage.

If you have an older car (to be safe say 2000 or newer) that requires premium gas then you MUST run premium gas, because the car has no way to know what the grade of fuel is so it cannot compensate when you use regular. The car also doesn't know when predetionation is occurring and damaging the engine.

Cliff Notes: Consumer reports type people should really stay out engineering things. Use the fuel recommended by your manufacturer.

** Last note. The energy potential of "premium" isn't more than regular, it just combusts slower (this is a layman definition please don't freak out people who actually know what I'm talking about).

 

[Art&Science]

The problem isnt octane. the problem is that damn alcohol.

Agreed. If you can, run straight gasoline and avoid blended fuels.

http://www.pure-gas.org/

They have a smartphone app also.

I do not use blended fuels (and by blended I mean fuels containing alcohol).

 

[T2urtle]

While I'm tuned on 93. And have no choice in that matter. I'm more angry about the spread of 87 vs 93.

Ex. Few years back 87 was $2.99, 89 was $3.09 and 91/93 was $3.19. Filled up yesterday it was 87 for $2.99, 89 for $3.49 and 93 was $3.99.

Explain what new process makes the spread so much more. Back then I didn't care about the 20 cents times 20gals. But now we are talking $1 x20galloons. It gets annoying.

 

[Pacfanweb]

Welcome to the 90's. I guess some folks don't know this, though, so it bears repeating every so often.

 

[pauldun170]

Here is my tried and true method
Look in owners manual
Use what manufacturer recommends
call it day

 

[Ferzerp]

Thank you for this wall of text on a topic that the audience of the garage already knows about. I guess?

 

[Pacfanweb]

Here is my tried and true method
Look in owners manual
Use what manufacturer recommends
call it day

Yep. If it doesn't say "premium recommended" or "premium required", then premium is a waste of money.

 

[Ferzerp]

Yep. If it doesn't say "premium recommended" or "premium required", then premium is a waste of money.

Except in those few cases with a fuel map that actually will give benefit from higher octane (e.g. last gen v6 mustang IIRC).

 

[Ackmed]

I run 93 100% gas in one car, and 93 10% ethanol in my other. Both would run very sub par on 87. My first is an older car, my second requires it.

While I'm tuned on 93. And have no choice in that matter. I'm more angry about the spread of 87 vs 93.

Ex. Few years back 87 was $2.99, 89 was $3.09 and 91/93 was $3.19. Filled up yesterday it was 87 for $2.99, 89 for $3.49 and 93 was $3.99.

Explain what new process makes the spread so much more. Back then I didn't care about the 20 cents times 20gals. But now we are talking $1 x20galloons. It gets annoying.

Pisses me off too, used to be 10 cents to go up a grade, now it is far more. Money grabbing assholes.

 

[jlee]

The problem isnt octane. the problem is that damn alcohol.

How so?

<-- disagrees

 

[mmntech]

Ethonol has less energy density than gasoline so the theory goes that you lose horsepower or fuel economy. A lot of the supposed benefits of ethanol are also pretty dubious. Particularly since it was being marketed as being more environmentally friendly. It's mostly just a fat subsidy to corn farmers.

Here is my tried and true method
Look in owners manual
Use what manufacturer recommends
call it day

Adding to this: if you don't want to spend money on premium gas, don't buy a car that says it needs premium gas. You can even buy luxury cars that run on regular. Lincolns for example. Or go for broke and get a Model S. Doesn't need gas at all. :thumbsup:

 

[Pacfanweb]

Except in those few cases with a fuel map that actually will give benefit from higher octane (e.g. last gen v6 mustang IIRC).

That would be the "premium recommended" vehicles. And what benefit would the get? More HP?
That would be subjective as to whether it's "worth it".

If it gets better fuel mileage, I'd just about bet that the gain would not be enough to offset the higher cost.

 

[Ferzerp]

That would be the "premium recommended" vehicles. And what benefit would the get? More HP?
That would be subjective as to whether it's "worth it".

If it gets better fuel mileage, I'd just about bet that the gain would not be enough to offset the higher cost.

No. It wouldn't be. This vehicle only ever lists 87 as recommended fuel, but happens to handle higher octanes properly and makes more power on them. Usually, there is no map for running higher than the recommended fuel, so any extra spent is a waste. In this specific case, that isn't true. It will make more power on the higher octane.

 

[Herr Kutz]

While I'm tuned on 93. And have no choice in that matter. I'm more angry about the spread of 87 vs 93.

Ex. Few years back 87 was $2.99, 89 was $3.09 and 91/93 was $3.19. Filled up yesterday it was 87 for $2.99, 89 for $3.49 and 93 was $3.99.

Explain what new process makes the spread so much more. Back then I didn't care about the 20 cents times 20gals. But now we are talking $1 x20galloons. It gets annoying.

The spread between octane levels is 20 cents at most places in my area.
89 price = 87 price + 20 cents
91/93 price = 89 price + 20 cents

More reasonable than what you're being charged, but still expensive imo.

 

[cabri]

The spread between octane levels is 20 cents at most places in my area.
89 price = 87 price + 20 cents
91/93 price = 89 price + 20 cents

More reasonable than what you're being charged, but still expensive imo.

For years, it used to be $0.10 between grades.
Then started being $0.20-0.30

Noticed that this past weekend, that many stations were $0.50 between grades.

Marketing :thumbsdown:

 

[Jumpem]

Who would buy a car which is tuned for performance and costs more, and then put cheap gas in it?

 

[jlee]

Ethonol has less energy density than gasoline so the theory goes that you lose horsepower or fuel economy. A lot of the supposed benefits of ethanol are also pretty dubious. Particularly since it was being marketed as being more environmentally friendly. It's mostly just a fat subsidy to corn farmers.



Adding to this: if you don't want to spend money on premium gas, don't buy a car that says it needs premium gas. You can even buy luxury cars that run on regular. Lincolns for example. Or go for broke and get a Model S. Doesn't need gas at all. :thumbsup:

Energy density is an entirely different topic than octane. If we're talking economy, then yes - gasoline is preferable. If we're talking power, E85 is up there (or better than) race gas.

 

[SSSnail]

For years, it used to be $0.10 between grades.
Then started being $0.20-0.30

Noticed that this past weekend, that many stations were $0.50 between grades.

Marketing :thumbsdown:

It's not just marketing, but it's a "requirement" from a lot of automobile manufacturers. If the owner's manual say "Premium", it's what you put in the tank. Gas companies know this, so they make sure to maximize their profits.