Article I came across in USA Today that I thought was interesting.

https://www.usatoday.com/story/money/cars/2017/04/26/higher-gas-octane-could-boost-performance----and-price/100938746/

To summarize car manufacturers feel higher octane fuels are a good way to boost MPG (In the US).

That's great and all but I question the validity of the primary source since the journalist didn't understand that 98 octane in Europe (RON) roughly equates to US 93 R+M/2

Along with higher prices at the pump. Just another way to make us pay so they can save money.

No thanks

Meanwhile in CA... the Air Resource Board looks to ban 91 and 89, as cars that require those fuel are higher performing and less economical. Also a 200% new car tax on anything not a Hybrid or Plug-In.

I get better MPG out of my 328i and 118i with lower octane. (95 eur= 91 US)

david in germany wrote

I get better MPG out of my 328i and 118i with lower octane. (95 eur= 91 US)

Unless it's based on Ethanol content....this makes no sense.

HawkeyeGeoff wrote

david in germany wrote

I get better MPG out of my 328i and 118i with lower octane. (95 eur= 91 US)

Unless it's based on Ethanol content....this makes no sense.

91 US is what it's designed for. When we moved from CA to TX, the jump from 91 to 93 actually lowered both of our cars (an M Coupe and a 135i) average mpg slightly. Of course the N54 1er was busy destroying HPFP's so I never really paid it much thought.

Red Bread wrote

91 US is what it's designed for. When we moved from CA to TX, the jump from 91 to 93 actually lowered both of our cars (an M Coupe and a 135i) average mpg slightly. Of course the N54 1er was busy destroying HPFP's so I never really paid it much thought.

Probably because you could run more boost in them

JsL wrote

Meanwhile in CA... the Air Resource Board looks to ban 91 and 89, as cars that require those fuel are higher performing and less economical. Also a 200% new car tax on anything not a Hybrid or Plug-In.

Wait, wasn't there a thread talking about how CA is the greatest state in the Union. Congratulations now your local government gets to pick what car you should drive.. Gee where do I remember shit like this going down, oh yea Communist Eastern Europe and the USSR.

JsL wrote

Meanwhile in CA... the Air Resource Board looks to ban 91 and 89, as cars that require those fuel are higher performing and less economical. Also a 200% new car tax on anything not a Hybrid or Plug-In.

LoL idiots.

JsL wrote

Meanwhile in CA... the Air Resource Board looks to ban 91 and 89, as cars that require those fuel are higher performing and less economical. Also a 200% new car tax on anything not a Hybrid or Plug-In.

Isthisrealtea?

JsL wrote

Meanwhile in CA... the Air Resource Board looks to ban 91 and 89, as cars that require those fuel are higher performing and less economical. Also a 200% new car tax on anything not a Hybrid or Plug-In.

Seriously?? That blows man.

I, too, question the validity based on the octane numbers he posted from Europe vs. the U.S. That said, the rest of the article is correct. I don't have a problem paying a few extra dollars for higher octane fuel if it increases the peformance (which it will if the engine is tuned for it and that's why so many of us tune our existing cars to optimize for the existing gasoline octane levels we put into it) and efficiency. That said, I see utter fail in the public's eyes coming. Any increase in price will be the shocker that installs ear plugs in the masses making everyone deaf to the explaination of its benefits and how it all works. The enviro-crazies want more effciency and cleaner air and this is just one way to easily help achieve both...too bad none of them will want to pay for it, let alone know how and why it works. They'll all be too fixated on the price and the fact that it's still a solution using a fossil fuel derivative while berrating anyone who wouldn't rather throw extra money into a less powerful, less enjoyable Hybrid Kia.

Meanwhile in CA... the Air Resource Board looks to ban 91 and 89, as cars that require those fuel are higher performing and less economical. Also a 200% new car tax on anything not a Hybrid or Plug-In.

Link? I couldn't find anything about this.

HawkeyeGeoff wrote

Unless it's based on Ethanol content....this makes no sense.

You should do a bit of research on it. Higher octane does not equal more power. Higher octane does allow for more aggressive timing in the engine. The lower octane is less stable than higher octane. you should run the lowest octane your vehicle can take for the most power and efficiency.

ShocknAwe wrote

That's great and all but I question the validity of the primary source since the journalist didn't understand that 98 octane in Europe (RON) roughly equates to US 93 R+M/2

Right, you are correct. It's a different calculation. Europe 98=US 93 octane.

I would think there would be more resistance in Europe since their gas is much more pricy.

JsL wrote

Meanwhile in CA... the Air Resource Board looks to ban 91 and 89, as cars that require those fuel are higher performing and less economical. Also a 200% new car tax on anything not a Hybrid or Plug-In.

It was meant to be a joke, but CA is the worst when it comes to these things.

david in germany wrote

You should do a bit of research on it. Higher octane does not equal more power. Higher octane does allow for more aggressive timing in the engine. The lower octane is less stable than higher octane. you should run the lowest octane your vehicle can take for the most power and efficiency.

This isn't entirely true. There exist vehicles where "premium fuel is recommended for maximum performance". I owned a 1993 Nissan Maxima SE that fell into this category. There are modern Toyota's and Cadillac's (just two examples) the fall into this category as well. Their ECU's are set, specifically, to run the lowest and highest octane gasoline and will adjust to perform better (i.e. produce more, verifiable HP) if higher octane fuel is used. This is not to be confused with, say, the clause in your BMW owner's manual that says basically "you can use 87 octane if you absolutely have to, but fill it up with premium as soon as you possibly can". This statement in the owners manual is always in cars that are designated "Premium Unleaded Fuel Only" (I have seen it in every manual from Mercedes, Audi, and BMW that I've owned from model years 1995-2016). If you have no such statement regarding premium fuel, then you are indeed pissing away money putting in more expensive gas as the ECU will not adjust parameters to give you better performance. Then, of course, there's those of us with tuned engines where you really should use fuel with the octane rating required by the tune that's flashed.

davis449 wrote

This isn't entirely true. There exist vehicles where "premium fuel is recommended for maximum performance". I owned a 1993 Nissan Maxima SE that fell into this category. There are modern Toyota's and Cadillac's (just two examples) the fall into this category as well. Their ECU's are set, specifically, to run the lowest and highest octane gasoline and will adjust to perform better (i.e. produce more, verifiable HP) if higher octane fuel is used. This is not to be confused with, say, the clause in your BMW owner's manual that says basically "you can use 87 octane if you absolutely have to, but fill it up with premium as soon as you possibly can". This statement in the owners manual is always in cars that are designated "Premium Unleaded Fuel Only" (I have seen it in every manual from Mercedes, Audi, and BMW that I've owned from model years 1995-2016). If you have no such statement regarding premium fuel, then you are indeed pissing away money putting in more expensive gas as the ECU will not adjust parameters to give you better performance. Then, of course, there's those of us with tuned engines where you really should use fuel with the octane rating required by the tune that's flashed.

What is "premium" in this case? Premium is not an octane rating it is an octane range. The industrial standard is 91 and up is premium.
As mentioned before, in my 335i when I am running my aggressive tune I must run the higher 95 octane (98 here in Germany)
When I say run the lowest octane your car can take I am referring to the lowest octane the manufacturer recommend (look inside your filler door)

JsL wrote

It was meant to be a joke, but CA is the worst when it comes to these things.

But amazing how many people believe it because it supports their belief system.

In the North East we had Sunoco 94 oct. My chipped:D A4 B5 loved that stuff. I remember the day i pulled up and the Sunoco reps where changing the yellow octane number stickers on the pumps. They removed the 94 sticker and placed a 93 sticker.........that was a sad day for auto gurus
With Manufactures running small liter engines with big boost, i would think higher octane would be a blessing. However, the tyrannical EPA wouldnt allow that. Its gonna be the auto industry pushing Trump, and Trump telling the EPA to scram......

Stop messing around with all that fuel and fill er up with some Avgas 100LL.

Cuz5150 wrote

In the North East we had Sunoco 94 oct

Ultra 94. Also had 86 at that same pump. Be thankful 93 is still available.