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Regular or Premium?

  • Regular

    Votes: 24 75%
  • Premium

    Votes: 5 16%
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    Votes: 3 9.4%

Gasoline....Regular or Premium?

50K views 36 replies 19 participants last post by  CorsaKoup  
#1 ·
Howdy, all,
Yes, I know this debate over 87, 90, or 91 octane gas rages on, but I'm curious as to what you all are really putting in your tanks.

Sometimes, we hear that now the majority of engines across the board, even ones where premium is "recommended," really don't run any better on it than on regular gas. In fact, I have read that cars meant to run on regular can actually do worse on premium. ?

But, what do you, personally, actually prefer? My old MINI "recommended" premium, and that's all she got. Out of habit, I'm thinking of using premium for my new baby Kia. But should I? :confused:

I open the floor to you!

PJ
 
#2 ·
I only run 94 in my H22 civic, but run regular in my dx. When I get my forte I'll most likely run 94 octane
 
#5 ·
+1 not to high not to low
 
#6 ·
Using anything more than 87 octane is a waste of money. Don't believe me? Search for the hundreds of posts about it. I won't bother explaining it here. Unless you're turbo'd or the regular is 10% and the higher grade is 0% ethanol, then you're wasting your money! PERIOD!
 
#7 ·
The owner's manual says

"Your new KIA vehicle is designed to use
only unleaded fuel having a pump octane
number ((R+M)/2) of 87 (Research
Octane Number 91) or higher..."

I personally use 87. You can use a higher octane, but you would be wasting your money. Octane doesn't determine the quality of gasoline but rather the amount of compression gasoline can have before detonating...
 
#8 ·
stumbled across this..
"octane isn't added to the fuel, it's a rating.

The octane rating is not a measure of power or energy, it's merely a measure of the burn time. The longer it takes to completely burn the fuel in your cylinder, the higher the octane rating. If your car requires 87 octane and you put a higher octane in, your engine's computer will detect the slower burn time and adjust the ignition as needed to compensate for the different fuel. This is why you're told to "not waste your money" on higher grades of gasoline.

The flip also holds true for the most part. If you burn a lower grade than recommended, your car will adjust, but not as efficiently. You will see a difference in performance and economy, but nothing earth shattering.

That being said, don't ever buy midgrade (plus), it's the biggest ripoff out there. While the price is midway between regular and premium, the actual mix ratio is 2 parts regular to 1 part premium. You get the same additive package as the regular fuel as well. You're better off buying 5 gallons of premium, then 10 gallons of regular. You'll pay less overall and get the additional additives most retailers reserve for their premium fuels.

You're better off buying a regular grade of a quality fuel than a premium grade of some discount product. I had a friend with an Infiniti and she ran Wal-Mart premium in it. I tried to convince her that she just spent almost 50K on a car and now she was going to cheap out a couple hundred bucks a year for some garbage premium, but she just never understood. Until, that is, her mechanic pulled her injectors and told her to run better fuel through it instead of paying him $1500 to replace her injectors every 2 years...
Source(s):

I work for one of the world's largest oil comapnies, managing fuels inventories across the US."
 
#27 ·
stumbled across this..
"octane isn't added to the fuel, it's a rating.

The octane rating is not a measure of power or energy, it's merely a measure of the burn time. The longer it takes to completely burn the fuel in your cylinder, the higher the octane rating. If your car requires 87 octane and you put a higher octane in, your engine's computer will detect the slower burn time and adjust the ignition as needed to compensate for the different fuel. This is why you're told to "not waste your money" on higher grades of gasoline.

The flip also holds true for the most part. If you burn a lower grade than recommended, your car will adjust, but not as efficiently. You will see a difference in performance and economy, but nothing earth shattering.

That being said, don't ever buy midgrade (plus), it's the biggest ripoff out there. While the price is midway between regular and premium, the actual mix ratio is 2 parts regular to 1 part premium. You get the same additive package as the regular fuel as well. You're better off buying 5 gallons of premium, then 10 gallons of regular. You'll pay less overall and get the additional additives most retailers reserve for their premium fuels.

You're better off buying a regular grade of a quality fuel than a premium grade of some discount product. I had a friend with an Infiniti and she ran Wal-Mart premium in it. I tried to convince her that she just spent almost 50K on a car and now she was going to cheap out a couple hundred bucks a year for some garbage premium, but she just never understood. Until, that is, her mechanic pulled her injectors and told her to run better fuel through it instead of paying him $1500 to replace her injectors every 2 years...
Source(s):

I work for one of the world's largest oil comapnies, managing fuels inventories across the US."
Now this is something I noticed the hottest females are always at the cheapest gas stations. I think the hotter they are the less they like to spend there own money. js
 
#10 ·
I wasn't aware of Wal Mart refining oil into gasoline..... my understanding of these independents is that they get the overflow or by contract get their gas from wholesale distributers that may ship them BP/Sunoco/ Mobil.. what ever is available... as far as I know there is no such thing as Murphy/Wal Mart gasoline... perse... you may be getting Chevron supreme and not know it.. If anyone really knows the scoop it would be approceiated. i just sent an e mail to Murphy Oil asking them for comparitive information related to their gasoline and their competitors. Hopefully I will get information.. not a corporate statement.. we will see..
 
#11 ·
I've already tried this with my old Dakota V-8, and the Forte. I found no difference in fuel economy or engine performance for those engines designed to run on 87.

I won't though fill up after a heavy rain, nor will I even consider a station that has a tanker truck sitting there....both of which are possibly myths but I'd rather not get water or debris in my tank.
 
#16 ·
When the tanker truck is filling the underground tank, it stirs up dirt, sludge and whatever else that may be in the bottom of the tank, which eventually settles to the bottom after a period of time after the truck has delivered the fuel. (Hence the whole dont fill while the truck is there) Granted modern stations have filters to capture particles and our cars have fuel filters as well so the likely hood of engine trouble is extremely low. Although I'd prefer not to get dirt and other particles into the tank and into my fuel filter in the first place. I just do it as a precaution....I don't let the fuel get to a point where it's critical that I need to stop at the first station that I see anyways.
 
#14 ·
Well, Walmart/Kroger/QT all are lowest bidders. They get cheap stuff that the bigger guys don't want/need or isn't inspected for quality. Chevron, BP, or the likes own their own refineries and storage tanks. So all their stuff is direct, without going through a third party, which ensures quality control.
 
#15 · (Edited)
Edit: Sorry Devil, meant to pull that first part out.

The top 8 or so producers own 56% of the oil refineries. All gas in an area is going to come from the same refinery. If Chevron, BP, etc happens to own the most refineries than this is why they get most of their gas from their own production... not because they like quality control. Walmart gets their gasoline from these refineries as well. The difference between the brands is the additives. As the truck leaves the refinery these are added based on what the customers pays for.
 
#20 ·
89, and I go mostly to Shell, Irving, Hess or Citgo. The onyl one I stay away from is Mobil, which is always pricey. I've never tried 87 or 91-93 in my Forte Koup, though I have wondered about 91 from time to time.
 
#22 ·
I def don't buy arco, Safeway or other grocery store gas, I switch up the actual gas station I use but only shell...I think legally every gas should have to list the ingredients they've added or not added so the consumer can make an informed decision about what they put in their car, if I was drivin a $100,000+ car I'd bother doing all the research before fueling up anywhere, but I'm comfortable with what I use
 
#28 ·
Ahahahahaha!!!
 
#29 ·
I run 87 in my koup , will only use 87.

But I will say. That I'm fond of chevron fuel. Every vehicle I've ever owned , runs best on chevron. Especially my elky... Just ran so much better.


Sent from my iPhone w/Wifi using Autoguide
 
#31 ·
I have never had a car that didn't run great on any fuel I have ever put in it. I have herd people say don't put ARCO gas in your car but will drive to other gas satastions that sell BP fuel as well. So on and so forth. I think it's a placebo effect. If you truly believe the car runs better on a certinain gas it will. But if you believe the way I do your car will run great on any gas. I have put all sorts of fuel in my cars over the years and never had any problems with any gas.
 
#32 ·
I personally know of a couple people who have had engine failure due to poor quality fuel...I think assuming that all fuel is equal is ridiculous as what in the consumer market is truly equal in quality? 9 times out 10 you get what you pay for, that other 1 being a Honda civic.
 
#33 ·
How come you guys get 87 89 91 fuel octane but they only sell 95( regular ) and 98 ( premium ) here. I think our 95 is your 89 and our 98 is your 91 or something ..
 
#34 ·
Off wikipedia :

''Octane rating is measured relative to a mixture of 2,2,4-trimethylpentane (an isomer of octane) and n-heptane. There are different conventions for expressing octane ratings, so a fuel may have several different octane ratings based on the measure used. Research octane number (RON) for gasoline varies with country. In Finland, Sweden, and Norway, 95 RON is the standard for regular unleaded petrol and 98 RON is also available as a more expensive option. In the UK, ordinary regular unleaded petrol is 91 RON (not commonly available), premium unleaded petrol is always 95 RON, and super unleaded is usually 97-98 RON. However, both Shell and BP produce fuel at 102 RON for cars with high-performance engines, and the supermarket chain Tesco began in 2006 to sell super unleaded petrol rated at 99 RON. In the US, octane ratings in unleaded fuels can vary between 86 and 87 AKI (91-92 RON) for regular, through 89-90 AKI (94-95 RON) for mid-grade (European premium), up to 90-94 AKI (95-99 RON) for premium (European super).''



So I guess 98 is premium but harms the engine.. hmmm
 
#35 ·
Off wikipedia :


So I guess 98 is premium but harms the engine.. hmmm
Hi, Rawad,
I re-read your info (thank you for digging that up), but I don't get why you said that 98 premium would harm an engine. ? I don't see where it said that...am I missing something. :confused:

danke schoen,
PJ
 
#37 · (Edited)
Higher octane doesn't mean faster combustion. Octane serves one purpose. It's added to gasoline to prevent pre-detonation, which can sometimes occur in higher-compression or forced-induction engines. Spark knock has the same effect as hitting the tops of the pistons with a hammer, because the force of pre-detonation hits the pistons while they're still traveling upward on the compression stroke. Octane helps the gasoline resist detonating before the spark plug fires, saving your high-compression or TC / SC engine from the damaging effects of pre-detonation. A Forte Koup doesn't have particularly high compression, nor is it turbocharged, so it's very unlikely to experience spark knock. There is sufficient octane in 87 to keep pre-detonation under control. My Mazdaspeed 6 required 93 octane due to using more than 17psi of boost. If you run 87 octane in a car like that, the computer will back off the spark timing and boost pressures.

Higher octane won't harm anything, it just won't do anything on low-compression & normally aspirated engines. It's been said that using high octane fuels in small engines (like lawnmowers, etc) can cause excessive carbon buildup, but I've never seen it first hand. Before I knew any better, I ran 93 octane in my 1993 Plymouth Sundance V6 for 5 years and 73,000 miles and it was running like a brand new car the day I traded it in. It won't hurt anything, it's just a waste....as I later discovered.