87 octane

[Tommm]

Originally Posted by Stubbie Blue

It's a psychological marketing thing and it's in your best interests to realize this.

The salesman wants to get as much money out of you as possible so they do NOT want you to look at the percentage difference because it is not justified. In your example, the sport options do not make the car 25% better even though they cost 25% more.

Instead, they DO want you to think about it in dollar terms, and furthermore they will try to divide it up into smaller portions to make it sound like less. E.g. $6,000 in options divided up over a 60 month loan is 'only' $100 per month. They can even divide it up some more to make it seem like nothing: 'oh that's just $3 per day, less than a Starbucks'.

Thinking in percentage terms keeps things in check because it is constant and not affected by those mind games.

Back in the mid 90s my Acura Legend Coupe had 230hp and a E36 M3 with the same HP cost about 30% more new. I owned both, and I didn't play with percentages on either purchase. Is a M3 30% better than a Legend?

I don't buy the percentage argument, and what do you mean in my best interest? I guess if I don't buy your argument I am foolish, and you are helping me by saying it is in my best interest. Sorry, blaming it on a salesman doesn't fly. When my buddy told me he just traded in his Porsche I confirmed with a few people that the price was fair. When I walked into the dealer I didn't weigh percentages. To decide if the price was fair based on its condition I didn't add or subtract percentages for a ding or tire wear, but did add and subtract dollars. I cut the check, and that was it. That was how I bought and sold about 50 cars. When it was between a 323ci or V6 Mustang for my daughter, percentages never came into play.

On the other hand, percentages come into play a lot when I analyze my 401K.

[JimVonBaden]

Originally Posted by Tommm

Then what was the point? The cheapest station by me was 2.59/3.39 that's 30% more. What is the point? The difference between steps is relatively static compared to the price of each grade, so the percentage fluctuates while the cost per mile is static.

At 25 mpg it is 3.2 cents a mile more. When it was a dime step each grade it was .8 cents a mile. Over 15,000miles a year that is $480 v $120.

Now it is time for the experts (aka jackasses) to say if you cant afford to throw away $480 a year you don't deserve to drive the car you purchased.

There is a reason rich people are rich. They don't needlessly waste money.

I doubt they worry about the percentage of waste either.

[Happy Jose]

I believe BMW says high octane is REQUIRED. I guess some knotheads don't understand the meaning of words or don't know how to use a dictionary.

[Tommm]

Originally Posted by Happy Jose

I believe BMW says high octane is REQUIRED. I guess some knotheads don't understand the meaning of words or don't know how to use a dictionary.

I believe that is incorrect. I believe the owners manual for the two non M naturally aspirated BMWs currently in my stable say it is recommended. I also believe similar verbiage is in the owners manual for the two Volvo V8s in my stable.

Off the top of my knothead I believe the manuals say that premium will get the maximum power, however lower octane fuel may be used with the tradeoff being lower performance. If I cared enough I would search the interwebz for confirmation. Since senility hasn't hit me yet I will go with my recollection. If someone cares more than me... Search is your friend.

[JimVonBaden]

Originally Posted by Happy Jose

I believe BMW says high octane is REQUIRED. I guess some knotheads don't understand the meaning of words or don't know how to use a dictionary.

And some idiots are sheep.

[MightyMouseTech]

Originally Posted by Tommm

I believe that is incorrect. I believe the owners manual for the two non M naturally aspirated BMWs currently in my stable say it is recommended. I also believe similar verbiage is in the owners manual for the two Volvo V8s in my stable.

Off the top of my knothead I believe the manuals say that premium will get the maximum power, however lower octane fuel may be used with the tradeoff being lower performance. If I cared enough I would search the interwebz for confirmation. Since senility hasn't hit me yet I will go with my recollection. If someone cares more than me... Search is your friend.

My E90 328 with N52 says minimum 91 octane. My 135i with N55 says to use 91, but minimum 89.

[chris_flies]

Originally Posted by MightyMouseTech

My E90 328 with N52 says minimum 91 octane. My 135i with N55 says to use 91, but minimum 89.

Odd, my N52 128i says 87 minimum, 91 recommended.

From my 2009 owner's manual under "Required fuel:"

"Super Premium Gasoline/AKI 91
This gasoline is highly recommended. However, you may also use gasoline with less AKI. The minimum AKI rating is:
-128i: 87
-135i: 89
If you use gasoline with this minimum AKI rating, the engine may produce knocking sounds when starting at high outside temperatures. This has no effect on the engine life."

In the 2013 manual, "BMW recommends AKI 91." And for the minimum fuel grade "BMW recommends AKI 89."

I wonder why they didn't make the distinction in the 2013 manual between the 128i and 135i...odd

[MightyMouseTech]

Originally Posted by chris_flies

Odd, my N52 128i says 87 minimum, 91 recommended.

From my 2009 owner's manual under "Required fuel:"

"Super Premium Gasoline/AKI 91
This gasoline is highly recommended. However, you may also use gasoline with less AKI. The minimum AKI rating is:
-128i: 87
-135i: 89
If you use gasoline with this minimum AKI rating, the engine may produce knocking sounds when starting at high outside temperatures. This has no effect on the engine life."

In the 2013 manual, "BMW recommends AKI 91." And for the minimum fuel grade "BMW recommends AKI 89."

I wonder why they didn't make the distinction in the 2013 manual between the 128i and 135i...odd

Maybe the newer cars have more safeguards for lower octane? My E90 is a 2010, the 135i is a 2013.

[Tommm]

Originally Posted by chris_flies

Odd, my N52 128i says 87 minimum, 91 recommended.

From my 2009 owner's manual under "Required fuel:"

"Super Premium Gasoline/AKI 91
This gasoline is highly recommended. However, you may also use gasoline with less AKI. The minimum AKI rating is:
-128i: 87
-135i: 89
If you use gasoline with this minimum AKI rating, the engine may produce knocking sounds when starting at high outside temperatures. This has no effect on the engine life."

In the 2013 manual, "BMW recommends AKI 91." And for the minimum fuel grade "BMW recommends AKI 89."

I wonder why they didn't make the distinction in the 2013 manual between the 128i and 135i...odd

The turbo motors require higher octane than a normally aspirated motor.

Go by the owners manual, not the door.

Our 323Ci has a higher number in the door than the manual

[chris_flies]

Originally Posted by Tommm

The turbo motors require higher octane than a normally aspirated motor.

Go by the owners manual, not the door.

Our 323Ci has a higher number in the door than the manual

I know that. But BMW obviously decided that either a) it was too expensive to print two different numbers distinguishing 87 for the 128i and 89 for the 135i, or b) the 128i should've really had 89 as a minimum.

Knowing BMW now, I'd tend to think option a, honestly.

I do go by the manual, but I'm tuned, so I'm supposed to put in 91/93. I have put 87 in it while tuned, and it ran fine. Definitely had less power though. Ran perfectly on 87 before tuning, didn't notice any difference in power.

[MightyMouseTech]

The owners manual for the 135i says the same as what the fuel door says. I always run 94 octane in the car because it is tuned, and the DME can recognize "super" octane (93 and up) and take advantage of it. I do notice a difference between 94 and 91. With 94, first gear is pretty much useless with wheel spin. lol

Going to have to get a manual for the E90.

[Jeb_]

Not that there's going to much of a performance difference on a stock car, but my 2011 128i says a minimum of 91 in the fuel door. Up until a few weeks ago it had a N51 in. Presumably the call for higher octane allowed them to reach whatever emissions requirements and power targets. So it would seem that they are/were printing different fuel door labels depending on the engine, even within the same model.

[WDE82]

Originally Posted by Tommm

What grade do the teach algebra in? Been decades since I took that class, but even decades later, this isn't algebra, it is common sense. The fact that you cant support your argument with logic is proof it fails.

That's an argument from fallacy. It's only proof that I was done explaining why percentages are more relevant and easier to use for comparisons than absolute differences in some cases.

Originally Posted by Tommm

Back in the mid 90s my Acura Legend Coupe had 230hp and a E36 M3 with the same HP cost about 30% more new. I owned both, and I didn't play with percentages on either purchase. Is a M3 30% better than a Legend?

I don't buy the percentage argument, and what do you mean in my best interest? I guess if I don't buy your argument I am foolish, and you are helping me by saying it is in my best interest. Sorry, blaming it on a salesman doesn't fly. When my buddy told me he just traded in his Porsche I confirmed with a few people that the price was fair. When I walked into the dealer I didn't weigh percentages. To decide if the price was fair based on its condition I didn't add or subtract percentages for a ding or tire wear, but did add and subtract dollars. I cut the check, and that was it. That was how I bought and sold about 50 cars. When it was between a 323ci or V6 Mustang for my daughter, percentages never came into play.

On the other hand, percentages come into play a lot when I analyze my 401K.

There is no "percentage argument". It's just useful for comparison's sake. If I know that I spend $150/mo in fuel for 93 and I want to compare with 87 and I know 93 is 25% more than 87, then my monthly fuel spent on 87 would be about $150/1.25=$120. And yes, that's very basic alegbra. I'm just not writing out every single step because that'd be absurd.

I think you're having trouble with juggling multiple concepts in your head. Sometimes absolute comparison is obviously better. Sometimes percentages/proportions. Sometimes both need to be considered.

I don't even know why I'm replying to you. I must be super bored. Just shut up about this crap already.

[JimVonBaden]

Originally Posted by WDE82

That's an argument from fallacy. It's only proof that I was done explaining why percentages are more relevant and easier to use for comparisons than absolute differences in some cases.




There is no "percentage argument". It's just useful for comparison's sake. If I know that I spend $150/mo in fuel for 93 and I want to compare with 87 and I know 93 is 25% more than 87, then my monthly fuel spent on 87 would be about $150/1.25=$120. And yes, that's very basic alegbra. I'm just not writing out every single step because that'd be absurd.

I think you're having trouble with juggling multiple concepts in your head. Sometimes absolute comparison is obviously better. Sometimes percentages/proportions. Sometimes both need to be considered.

I don't even know why I'm replying to you. I must be super bored. Just shut up about this crap already.

Good idea. Take your own advice!

[Tommm]

Originally Posted by WDE82

I don't even know why I'm replying to you. I must be super bored. Just shut up about this crap already.

Ditto

[JimD]

For the first 58K miles I drove my 2019 e88, N52 I filled it with at least 89 octane. Occasionally I put i 93 octane. I averaged 26.7 mpg. I now fill with 87 octane. I noticed the manual supports it in my case (i.e. 87 minimum is what my manual says) and I did not notice any difference in normal driving. I averaged the next 13K miles but haven't updated my spreadsheet for quite awhile. But 13K miles is not a tiny sample and my mileage improved to 27.4 mpg. Some day I will grab the notebook in my car and total up the last 20K+. But I don't think it will change much.

If you want the most performance, use higher octane. If you want to spend the minimum possible, use the lowest octane recommended for your car. But also pay attention to indications of detonation. My second car used to be a Suzuki SUV with a 2.7l V6. 87 was recommended. But it pinged badly in hot weather, especially towing a trailer unless I used higher octane. If my BMW pinged at all on 87 I would switch back to mid grade or higher. But it doesn't, including while towing.

I believe it is also possible that your car will run enough better for your mileage to be better with higher octane. I doubt that happens a lot, the higher heat value of the lower octane fuel is higher (i.e. it has more energy in it). But it depends on the car tune too. So if you use lower octane fuel to save money it is a good idea to keep track of at least 1,000 miles or so of gas mileage to be sure that is happening.

The best argument for using higher octane than you can justify by the car manufacturers input or your data is that the dollar per year difference is not high. Drivers of BMWs should be able to afford it. I just don't like wasting money. So I buy 87 octane shell gas most of the time.

There is also an argument that there are more or better additives in the higher octane fuel. Shell specifically states the additives are the same but doesn't specifically say anything I can find about the amount.

[Tommm]

Originally Posted by JimD

There is also an argument that there are more or better additives in the higher octane fuel. Shell specifically states the additives are the same but doesn't specifically say anything I can find about the amount.

If the gas is top tier all grades have the additives.

[gjm120]

Originally Posted by Tommm

If the gas is top tier all grades have the additives.

Not all additive packages are created equal. I think the main actor in Techron (PEA) is the best additive. It is in Chevron and Texaco gasolines and can be added from a bottle of Techron or Redline or Gumout (significantly larger doses from a bottle than you'll get from Chev/Tex gasolines.)

I've read that some additive packs can actually create a detergent build up but don't know whether to believe that or not.

Nothing really helps valve deposits on direct injection engines which is why people walnut blast their N54 or N55 engines.

We are really getting fleeced on premium gasoline as the price differential at the pump is somewhat more than the manufacturing or the spot market. The 'extra' differential is even greater with gaso from the majors. Around me Costco is by far the least expensive premium in both absolute and relative to 87. Unfortunately I'm not a Costco member. So I look for Valero (top tier) or go to a supermarket and drop in a little Techon.

[Tommm]

Originally Posted by gjm120

Not all additive packages are created equal. I think the main actor in Techron (PEA) is the best additive. It is in Chevron and Texaco gasolines and can be added from a bottle of Techron or Redline or Gumout (significantly larger doses from a bottle than you'll get from Chev/Tex gasolines.)

I've read that some additive packs can actually create a detergent build up but don't know whether to believe that or not.

Nothing really helps valve deposits on direct injection engines which is why people walnut blast their N54 or N55 engines.

We are really getting fleeced on premium gasoline as the price differential at the pump is somewhat more than the manufacturing or the spot market. The 'extra' differential is even greater with gaso from the majors. Around me Costco is by far the least expensive premium in both absolute and relative to 87. Unfortunately I'm not a Costco member. So I look for Valero (top tier) or go to a supermarket and drop in a little Techon.

Top tier is a rating that many manufacturers including BMW and GM are part of. They have a specification that top tier gas - al grades have to meet. It's not an additive, it is in what you get from the pump. Techron has nothing to do with it. That may be what Chevron calls it on their pumps.
Learn about it here. https://toptiergas.com/

[gjm120]

Originally Posted by Tommm

Top tier is a rating that many manufacturers including BMW and GM are part of. They have a specification that top tier gas - al grades have to meet. It's not an additive, it is in what you get from the pump. Techron has nothing to do with it. That may be what Chevron calls it on their pumps.
Learn about it here. https://toptiergas.com/

It's the quality of the detergent additive package that makes a gasoline Top Tier. Yes, Techron (which PEA is the primary active ingredient) is a trade name for Chev/Tex's additive pack. I along with others think PEA is the best additive for port injected engines.

You get the additive at the pump because it is added into the tanker truck at the terminal's loading rack.

[Tommm]

Originally Posted by gjm120

It's the quality of the detergent additive package that makes a gasoline Top Tier. Yes, Techron (which PEA is the primary active ingredient) is a trade name for Chev/Tex's additive pack. I along with others think PEA is the best additive for port injected engines.

You get the additive at the pump because it is added into the tanker truck at the terminal's loading rack.

Quality and quantity to get top tier rating. The top tier pumps I've seen over the years don't state that there is more detergent in the higher grade. Back in the day of cross fire fuel injection the car (or in my dad's case Astro van) was made to run on regular, but whenever I filled it up I put premium in so he would get some detergent. He did notice the difference, but being a depression child he refused to put premium in.

[gjm120]

Originally Posted by Tommm

Quality and quantity to get top tier rating. The top tier pumps I've seen over the years don't state that there is more detergent in the higher grade. Back in the day of cross fire fuel injection the car (or in my dad's case Astro van) was made to run on regular, but whenever I filled it up I put premium in so he would get some detergent. He did notice the difference, but being a depression child he refused to put premium in.

By quality of the additive pack of course I meant the quality x qty of the additives. Obviously a ml of very good additive can be better than a litre of poor additive. Just for reference, the typical additive injection rate at the truck loading rack is only about 100ppm.

From way back in my early working life, I know premium had a higher additive dose than lower grades for most brands. Don't really know, but, I would guess currently that is still the case.

Point of interest is that Costco mogas may have additive added at the pump
http://www.neiwpcc.org/tanks2013old/...13_Tuesday.pdf