[Gogators93]

Probably asked before but I could't find it in a search. Just curious how many people run regular 87 octane instead of Premium 93? Specifically for me would be the X540. I'm just curious as in researching, the common thought seems to be that BMW recommends 93 for all of their vehicles but some discussions seem to say that 87 is fine and the engines have the technology to adjust for lower octane gas, obviously at a cost to performance. But if I don't need that 10 horsepower loss 99.9% of the time, what the hell if it isn't hurting anything.

I get the point that if you are worried about the price of gas you shouldn't probably purchase something that cost this much but just really curious how many people use 87, or even 89 and if they have any issues?

[SJW]

I run 93 Shell 90%ish of the time. If I can't find it I use 91. I personally would never run anything below the recommended 91.

[MystroX5]

Always premium. I have a few empirical data examples of some of my PCA members over the years running regular (cheap gas) in various German cars that were required to run premium. Despite having lower performance by the computer adjusting to the lower octane rating, there have been injector problems fuel pump problems, etc....

I run the best gas I can find which is Sunoco 93 in everything.

[homerrr]

Octane has nothing to do with the cleanliness of the fuel. Use "top tier" (like Shell or Sunoco) fuel that contains detergents and meets a certain standard to keep your engine clean. This wil prevent dirty injectors and carbon build up, which can cause detonation.
Another issue is using low octane fuel. Octane number indicates at what pressure fuel will self ignite. The twin-turbo in your X5 40i provides higher pressure before combustion then a naturally aspirated engine. Obviously you want the ignition system to determine the moment of ignition. Using low octane may cause pre-ignition, which may be noticeable but can cause problems over time for sure.
Not the most scientific explanation but hope it helps people tace care of the car

[vladm]

Originally Posted by MystroX5

Always premium. I have a few empirical data examples of some of my PCA members over the years running regular (cheap gas) in various German cars that were required to run premium. Despite having lower performance by the computer adjusting to the lower octane rating, there have been injector problems fuel pump problems, etc....

I highly doubt that 87 is of any lower quality than 93 in terms of how clean it's compared to 93. It's produced/stored/hauled by the same refineries same processes, etc...

Pump and injectors and overall fuel supply system can not be damaged by a lower octane fuel, only by "bad", contaminated fuel.


Here is the kicker fact for you. The middle grade fuel is actually a mix of 93 and 87, that happens at the gas station. So if gas station has 91 as middle-grade (and it's OK to use according to the vehicle requirements), it's essentially 1/3 of an 87s and 2/3 of 93.

[Tenac]

If you are in a situation where you only have reg 87 it won't hurt. The X5 computer will adjust timing for it. But running it long term can cause damage to the internals and specially if a knock sensor fails (I have seen this put pistons in pieces, my grandfathers caddy). Yes fuel can be tested easily to show you are not running recommended octane and warranties can be voided because of this (also read the warranty disclaimer they have one on fuel).

My question to anyone why wouldn't you run the 91 recommend???

It cannot be cost savings bc you only save "about" $5 per tank if you filled it from 0 gallons and the cost was .25 more. Say you fill out 4 times a month that is $20 a month or $240 a year at a pretty extreme calculation. I didn't buy a SAV to be cost minded or fuel efficient.

It cannot be fuel mileage bc the cars knock sensors will retard the timing meaning less efficient combustion of the fuel its self more actual wet fuel going out the exhaust.

So why would you not run it, unless you simply didn't have it available????

[Paladin1]

Nothing below 91, and BMW recommends 89 as the minimum. There are several warning notices in the Owners Manual - probably the Ethanol content is the most important recommendation (maximum 10 percent). Using anything other than the recommended fuel in a $90k+ vehicle to save a few pennies may not pass the logic test for some, but likely won't cause anything but additional maintenance issues long term, which may or may not balance out any fuel savings. However, from the manual:

NOTICE
Fuel that does not comply with the minimum quality can compromise engine function or cause engine damage. There is a risk of damage to property. Do not fill with fuel that does not comply with the minimum quality.

"Quality" is not defined, but could certainly be interpreted as octane rating by the manufacturer.

[SCA]

This Shell recommendation sticker is on our week 40 M50i.

[MystroX5]

Originally Posted by vladm

I highly doubt that 87 is of any lower quality than 93 in terms of how clean it's compared to 93. It's produced/stored/hauled by the same refineries same processes, etc...

Pump and injectors and overall fuel supply system can not be damaged by a lower octane fuel, only by "bad", contaminated fuel.


Here is the kicker fact for you. The middle grade fuel is actually a mix of 93 and 87, that happens at the gas station. So if gas station has 91 as middle-grade (and it's OK to use according to the vehicle requirements), it's essentially 1/3 of an 87s and 2/3 of 93.

Not all do the mid grade mix.

[AnOldBiker]

It was mentioned that the 91 octane is mixed at the pump .... It is blended at the refinery or dispersion depot as 91 octane, the same as with the 87 and 93 octane just before it is put the trucks trailer. There is no mixing at the stations. All chemicals are to be added at that point of blending prior to shipping. Samples are drawn at specific times for testing to verify quality.

Now if this is accepted by BMW or not I'm not sure, but I was told by my stealership, if you use the 91 octane once in a while due to lack of 93 octane, this is fine. But if you're in a situation where there is only 87 octane, use an octane booster at that time. But do not use 87 all the time.

[Aliendrive]

My previous X3 went in for 45k oil change. The SA asked if everything was going good and I said gas mileage going down to try to get new spark plugs. When I picked up car they said they tested gas and I was over 10 percent ethanol and said I should watch where I buy gas. At that time I only used Shell gas and my area has the 10 percent max ethanol everywhere and summer gas formula. Needless to say they waited till next oil change for new spark plugs.

[Paladin1]

Originally Posted by AnOldBiker

It was mentioned that the 91 octane is mixed at the pump .... It is blended at the refinery or dispersion depot as 91 octane, the same as with the 87 and 93 octane just before it is put the trucks trailer. There is no mixing at the stations. All chemicals are to be added at that point of blending prior to shipping. Samples are drawn at specific times for testing to verify quality.

Now if this is accepted by BMW or not I'm not sure, but I was told by my stealership, if you use the 91 octane once in a while due to lack of 93 octane, this is fine. But if you're in a situation where there is only 87 octane, use an octane booster at that time. But do not use 87 all the time.

93 octane has somehow gotten into the conversation, but nowhere in the 2019/20 X5 Owners Manual is it mentioned. BMW recommends 91 octane (actually AKI 91) with 89 octane as a minimum. It's not necessary or beneficial to use a higher octane, and probably not beneficial or prudent to use a lower.

[Qsilver7]

Originally Posted by SCA

This Shell recommendation sticker is on our week 40 M50i.

The Shell recommendation is there because they're paying for the advertising. It's a real world example of "quid pro quo".

For example...they have renewed their "exclusive oil provider" recommendation by BMW up until the end of 2022:

[Aaaaaaaaa]

Buys $70k gas guzzling SUV
Wants to save $300 a year on gas and ruins engine

[dan321]

Originally Posted by Paladin1

93 octane has somehow gotten into the conversation, but nowhere in the 2019/20 X5 Owners Manual is it mentioned. BMW recommends 91 octane (actually AKI 91) with 89 octane as a minimum. It's not necessary or beneficial to use a higher octane, and probably not beneficial or prudent to use a lower.

In some areas, like Central Florida, neither 89 nor 91 Octane is available, so I use 93. I think there are quite a few areas where 93 is the norm for high octane.

[AnOldBiker]

Originally Posted by Paladin1

93 octane has somehow gotten into the conversation, but nowhere in the 2019/20 X5 Owners Manual is it mentioned. BMW recommends 91 octane (actually AKI 91) with 89 octane as a minimum. It's not necessary or beneficial to use a higher octane, and probably not beneficial or prudent to use a lower.

In my area, premium is 93 and I only get 91 when out of my area, sorry. But I wanted to say they blend at the depot, not the station, and as ordered per the state and federal regulations. Also, the stealership told me BMW recommends (91 octane +) and not use regular. If stuck using regular, add an additive to boost the octane rating.

[Sonny185]

Originally Posted by AnOldBiker

In my area, premium is 93 and I only get 91 when out of my area, sorry. But I wanted to say they blend at the depot, not the station, and as ordered per the state and federal regulations. Also, the stealership told me BMW recommends (91 octane +) and not use regular. If stuck using regular, add an additive to boost the octane rating.

Most mid-grade gasoline is sold today through what is called "blender" dispensers. The mid-grade is not blended at the terminal. To get the desired 89 octane for mid-grade, that blend comes from the 87 and either 91 or 93 octane storage to produce that 87 octane blend.

I sell gasoline dispenses and 85% of the gasoline dispensers sold today are blender type equipment at the island.

[Paladin1]

Originally Posted by AnOldBiker

In my area, premium is 93 and I only get 91 when out of my area, sorry. But I wanted to say they blend at the depot, not the station, and as ordered per the state and federal regulations. Also, the stealership told me BMW recommends (91 octane +) and not use regular. If stuck using regular, add an additive to boost the octane rating.

Should have clarified - won't hurt anything at all to use a higher octane rating than recommended. Just doesn't provide any measurable benefit and costs more; discussed ad infinitum on other forums. If that's all that's available, c'est la vie - just more per fill up. A modern car's computer will adjust to accommodate just about any commonly available range, but using lower than recommended octane ratings can cause premature ignition and eventual engine damage over time. A tank or two every now and then, not a problem. Newer engines are pretty tough these days, but chancing damage to a $15-20k engine by using less than optimum fuel to save money somehow doesn't make financial sense weighing all options.

[AnOldBiker]

Not sure where your at, but I just retired from the industry after 30+ years and that is not what anyone did that I knew.

We have blenders, but they did the blending prior to loading for delivery. Base stock gasoline is 74 octane and the chemicals added increased the octane to the ordered octane each load.

[Gogators93]

Originally Posted by Paladin1

93 octane has somehow gotten into the conversation, but nowhere in the 2019/20 X5 Owners Manual is it mentioned. BMW recommends 91 octane (actually AKI 91) with 89 octane as a minimum. It's not necessary or beneficial to use a higher octane, and probably not beneficial or prudent to use a lower.

That was my fault as the OP. It is just what I recall seeing at the Shell Station where I get fuel.

[maczrool]

Originally Posted by homerrr

The twin-turbo in your X5 40i

It’s a twin- scroll single turbo is it not?

[TurtleBoy]

Originally Posted by maczrool

It’s a twin- scroll single turbo is it not?

That is correct, it is a twin scroll turbo.