News, Super fuels truth will drive you mad. (fuel, octane, versus)

[John1960]

HARD-PRESSED motorists being lured into buying expensive 'premium' fuel are wasting their money, new research shows.

Oil firms are shelling out millions advertising pricey super fuels, promising drivers up to 25 PER CENT extra mileage from a tank.

Super fuels truth will drive you mad | The Sun |News

[theunbrainwashed]

I was always told that, if your engine was made for unleaded regular, then using unleaded premium won't make a difference. The cars that recommend using unleaded premium are usually upscale cars like Acura and Lexus which usually have high HP engines

[Narfcake]

Petrol in the UK goes by different ratings versus that here in the US, but yeah - unless the car's engine was designed for higher octane fuels, there won't be a difference. Even then, engines which are designed for premium might not have a huge penalty in fuel consumption when running regular. It all depends on how aggressive the computer reacts to detonation. As the adage goes, your mileage may vary.

With that said, my wagon, which is turbocharged, does yield higher 1.5 to 2 MPG more on premium vs. regular. That's enough to offset the price difference, so premium it gets.

[ferretkona]

Originally Posted by Narfcake

...With that said, my wagon, which is turbocharged, does yield higher 1.5 to 2 MPG more on premium vs. regular. That's enough to offset the price difference, so premium it gets.

Love to do the math on that. Somehow I doubt 10 cents more a gallon could equal 1.5 mpg improvement.

[piyf]

Originally Posted by theunbrainwashed

I was always told that, if your engine was made for unleaded regular, then using unleaded premium won't make a difference. The cars that recommend using unleaded premium are usually upscale cars like Acura and Lexus which usually have high HP engines

Did you really say High Horsepower, Acura and Lexus in the same sentence?

[Narfcake]

Originally Posted by ferretkona

Love to do the math on that. Somehow I doubt 10 cents more a gallon could equal 1.5 mpg improvement.

Different cars, different results. That's why I also said YMMV.

The wagon in context is a '91 Volvo 745Ti, B230FT/M46 with 243+k miles. It's called out in the owner's manual that premium is recommended.

I note down the mileage at every refueling. On regular, I yielded 20.7 - 21.3. In the periods before and after with premium, I yielded 22.0 - 23.4. This was repeated on several occasions.

250 miles / 21.0 = 11.90 gallons of regular.
250 miles / 22.7 = 11.01 gallons of premium.

Hence, paying $4.359 for premium nets out to be cheaper than paying $4.159 for regular.

[iTsLiKeAnEgG]

Originally Posted by danieloneil01

Did you really say High Horsepower, Acura and Lexus in the same sentence?

I'd say 380hp is fairly high.

[Donn2390]

This article is 20 year old facts, not a new bulletin...!

[415_s2k]

I had an ex-fiance who would always talk about this because she read an article about it, and her mom (who also thought her FWD Subaru wagon was RWD) was constantly going on about this.

One day, she came to pick me up in our car, which was a Jetta VR6. She gets out, I get behind the wheel, and then we start to head out. I look to see if the A/C is on, because it's not accelerating as well as it usually does, and feels a bit strained. Nope. A/C's off.

"You put 87 in, didn't you?"
"No!"
"Then what did you do to the car? It's riding like crap."
"Fine. I put 87 in. There's no difference."
"Then how come I could tell as soon as I started driving?"
"There is no difference."
"Yes there is, I could tell as soon as I started driving!"

In my parents' Town Car, it makes no difference. In their Corolla, it makes no difference. In the 2.0 Jetta we owned, it made no difference. In my old MG Midget, it made no difference. With a modern performance engine, it does, and if you don't think it does, I can tell you that you most likely have never driven a modern performance engine with both fuel grades in it (and before anyone comes out all limp-wristed like, "those aren't high performance engines!," they aren't economy engines either).

[evilnewbie]

The only time higher octane fuel will benefit your car is if your car has an engine built for the higher octane fuel... bottom line, no point in putting higher octane fuel in a car that was designed for regular unleaded... which is most cars... but if your car needs premium fuel, its better to put that in... but then everyone in this forum already knows that... lol...