[Nezil]

Over the last couple of weeks I've been looking at datalogs of my car with various BM3 OTS maps, and also with the stock map, and I'm finding a very worrying data point.

I've documented a lot of this in another thread, so I won't repeat all the data here, but to summarise:

I was finding 'Knock Detected' events in my data log with the Stage 1 91 octane OTS BM3 map, so I switched back to stock, logged again and found similar 'Knock Detected' events with the stock map.

Various forum members told me that I must have 'bad gas', and I was skeptical... I was filling up at Shell or Chevron, and large gas stations, not small ones. I've also deliberately filled up in different stations to avoid what might be a station passing 87 off as 91.

In order to test this theory though, I made a 3:1 blend of Sunoco SS100, which has an AKI of 100. (91*3+100)/4 = 93.25. I then took logs again of the Stage 1 and Stage 2 91 Octane OTS BM3 maps.

The 'Knock Detected' events disappeared, which seems to confirm the suggestion that the pump gas I used wasn't up to the task, but I was still getting a lot of timing corrections.

I had 2 gallons of SS100 left, so I decided to add this to the remaining few gallons in my tank, to get me to a theoretical 95.5 AKI blend. Again I captured logs.

This time, the timing corrections, while still present, were much more in line with what was expected, but keep in mind that this was for the 91 octane OTS map, and my tank had what should have been 95.5 AKI fuel...

I've now had Halim take a look at all of my logs, and he's saying that based on his experience, it looks like the pump gas that I'm using has an octane of around 88 AKI, even though it's being sold as 91!

I know that CA (or ACN - Arizona, California, Nevada) fuel is known to be not as good as the rest of the country, but 88 performance when being sold as 91, is that even possible, or legal?

I also know that there are a few forum members (e.g. UltraMagneticAL and tehboost) who are based in Southern California, and anecdotally appear to have 91 AKI fuel that isn't quite as bad as in the bay area.

My larger concern, is that our cars were designed to run on 93 AKI, and say 91 AKI minimum inside the fuel door and the owners manual. I'm seeing 'knock detected' events A LOT with standard pump gas on the stock map, which isn't a good thing. I'm actually worried that the fuel in the bay area may be causing long term damage to forced induction cars even without any modifications, and owners are simply unaware!

There are three main oil refineries in the bay area:

• Chevron in Richmond
• Shell in Martinez
• Valero in Benicia

It would be interesting to know which stations use which refineries, to try and see if one or more of these is producing 'bad gas' compared to the others.

I guess it should be obvious that Chevron stations are using gas from the Chevron refinery, Shell from Shell and Valero from Valero, but what about the others? 76, BP, Mobil, Arco, Costco, Independents etc.

Does anyone know if there is a way to have gas tested? I'm serious enough to say that there might be a class action law suit that could come out of this, if it's found that we're being sold under performing gas.

[Rick4345]

I wouldn't worry too much.

First of all, 91 is the MINIMUM octane rating. The owner manual states that you could experience engine knock at high temperature start ups. And yes, you may experience less performance with it.

The RECOMMENDED octane rating is 93.

As you can tell by your own experiment that one it two octane points make the difference.

[Nezil]

Originally Posted by Rick4345

I wouldn't worry too much.

First of all, 91 is the MINIMUM octane rating. The owner manual states that you could experience engine knock at high temperature start ups. And yes, you may experience less performance with it.

The RECOMMENDED octane rating is 93.

As you can tell by your own experiment that one it two octane points make the difference.

I think you're missing the point Rick4345. I'm saying that Bay Area fuel isn't performing like 91, and is therefore below the MINIMUM octane rating.

[Rick4345]

Originally Posted by Nezil

I think you're missing the point Rick4345. I'm saying that Bay Area fuel isn't performing like 91, and is therefore below the MINIMUM octane rating.

Is it all or just some??

It can be hard to find good gas. I have certain brands I like to use. Even they vary from location to location. I use a lot of "Top Tier" fuels and that seems to work. My favorite is VP Racing Fuels 93 octane. I know it's not a Top Tier fuel but my car runs great on it. I don't know if you have it there.

If you think you have a problem get a sample and document on video getting it. I'm pretty sure that you can find a lab that could test it.

[Nezil]

Originally Posted by Rick4345

Is it all or just some??

It can be hard to find good gas. I have certain brands I like to use. Even they vary from location to location. I use a lot of "Top Tier" fuels and that seems to work. My favorite is VP Racing Fuels 93 octane. I know it's not a Top Tier fuel but my car runs great on it. I don't know if you have it there.

If you think you have a problem get a sample and document on video getting it. I'm pretty sure that you can find a lab that could test it.

So far I'm finding it to be all... I've tried Costco, Chevron, Shell and 76, all with similar results. All are Top Tier.

VP Racing 93 isn't available here, unfortunately.

I think it will need a lab to test it... that's what I'm hoping someone on here will know how to do, and others in the bay area that might be interested in joining the fight / gathering data.

[gtaM2]

not sure how engines work but is it possible you had a bad fill up of gas in the past and you have some bad deposits resting in your tank for awhile?

[Nezil]

Originally Posted by gtaM2

not sure how engines work but is it possible you had a bad fill up of gas in the past and you have some bad deposits resting in your tank for awhile?

I don't think so... It's possible to notice a difference in engine behaviour via the logs, pretty much as soon as you add a few gallons of 100 AKI Race Gas, particularly if you reset engine adaptations to make sure you're starting from a clean sheet.

I've also been tracking the data logs over a few tanks now, and whilst I'd be prepared to accept a tank, or even two, of 'bad gas'. Right now, I'm struggling to actually find 'Good gas'!

[diesekte]

The state Dept of agriculture is usually interested in fuel quality...I'd reach out to them

[XProject]

Do you feel anything when you have "knock detected" or is it only noticed by the logs? I don't have BM3 so I'm not aware of these gas quality. I'm always filling Shell V-Power. It seems to be doing ok.

[Nezil]

Originally Posted by XProject

Do you feel anything when you have "knock detected" or is it only noticed by the logs? I don't have BM3 so I'm not aware of these gas quality. I'm always filling Shell V-Power. It seems to be doing ok.

I'm not sure if it's fair to say that I 'feel' something. It certainly doesn't feel like the car is stuttering. Perhaps a lower willingness to rev, but that might be placebo.

It's well known that using 91 Octane gas results in lower power and torque compared to using 93 94. The engine is capable of adapting to 91 without serious damage, but I believe using less than 91 could cause damage over a long period of time.

Any damage would probably be slow, so it wouldn't even be apparent yet; our cars are too new.

[cookiesowns]

Ouch.. that's no bueno.

Yeah I'm also in socal and I don't get any of what you see. The shell VPower+ Nitro station by my area generally has very good fuel quality.

If you have bimmerlink and a OBD, you can measure the fuel quality realtime and see what type of power it is pulling. Or also use ISTA+ to measure your fuel quality over time.

[Nezil]

Originally Posted by cookiesowns

Ouch.. that's no bueno.

Yeah I'm also in socal and I don't get any of what you see. The shell VPower+ Nitro station by my area generally has very good fuel quality.

If you have bimmerlink and a OBD, you can measure the fuel quality realtime and see what type of power it is pulling. Or also use ISTA+ to measure your fuel quality over time.

Oh... how do you do this with ISTA+? I don't have an iPhone so I can't use Bimmerlink, but would be interested in knowing what's possible in ISTA+!

[cookiesowns]

Originally Posted by Nezil

Oh... how do you do this with ISTA+? I don't have an iPhone so I can't use Bimmerlink, but would be interested in knowing what's possible in ISTA+!

Once you do a vehicle scan, click on the DME module and use "call ecu functions" then there should be some diagnostics method in there to get the fuel quality. If it's not there, then just search for fuel quality and there should be a measures plan to call up the information.

[Nezil]

Originally Posted by cookiesowns

Once you do a vehicle scan, click on the DME module and use "call ecu functions" then there should be some diagnostics method in there to get the fuel quality. If it's not there, then just search for fuel quality and there should be a measures plan to call up the information.

I'll take a look for this in about 15 minutes! Thanks.

[akkando]

Originally Posted by Nezil

I know that CA (or ACN - Arizona, California, Nevada) fuel is known to be not as good as the rest of the country, but 88 performance when being sold as 91, is that even possible, or legal?

Is there some way we can run a test on the gas itself to find out what it is in a lab? How much would that cost to have that done?

This makes it seem like tuning in the bay area or CA at all is foolish if you're going to use pump gas, maybe even driving a car that requires premium in this area is foolish?

If it runs out they're selling 88 gas as 91 that seems like a news story.

Highest prices gas in the country, second highest taxed gas in the country, but this most expensive gas in the country sold as 91 is really 88?

As a side note I notice my gas mileage isn't what it should be here in this area... related?

[Nezil]

Originally Posted by akkando

Is there some way we can run a test on the gas itself to find out what it is in a lab? How much would that cost to have that done?

I'm hoping someone on here might be able to suggest a lab, but I'll start reaching out to places like Blackstone, to see if they can recommend anyone.

One thing that concerns me is that the octane rating in the US is AKI, which is an average of the RON (Research Octane Number) and MON (Motor Octane Number). A gasoline with an AKI of 91, could have a high RON, and a lower MON. RON is a test more representative of a forced induction engine under load, so a high RON with a low MON wouldn't be a good fuel, even though it is technically 91 AKI.

It's difficult to find the RON and MON values for pump gas, but VP Racing and Sunoco do provide details for all of their racing fuels. Unfortunately there are so many different types of fuels, with Ethanol (oxygenated) and without, so it's difficult to draw any conclusions.

This makes it seem like tuning in the bay area or CA at all is foolish if you're going to use pump gas, maybe even driving a car that requires premium in this area is foolish?

That's exactly my concern. I'd love to be wrong, but I've not yet found a gas that works correctly in our engines. I do still have Valero to try, as that's the third refinery in our area. I'll also try Shell again, but it wasn't any better last time I tried.

If it runs out they're selling 88 gas as 91 that seems like a news story.

Highest prices gas in the country, second highest taxed gas in the country, but this most expensive gas in the country sold as 91 is really 88?

Exactly my point... I have my own selfish reasons for getting to the bottom of this - getting the best out of my car's tune, but with that aside, it seems like it would be a massive conspiracy if it turns out to be true.

The irony would be that our poor gas is supposed to be 'better' for the environment, but prevents cars from running more boost, which makes them more efficient, which is therefore bad for the environment. I realise that in our cars, the boost is used simply to get more power, but the trend these days around the world, but particularly in Europe, is to down size engines, and add more boost.

[akkando]

Originally Posted by cookiesowns

Ouch.. that's no bueno.

Yeah I'm also in socal and I don't get any of what you see. The shell VPower+ Nitro station by my area generally has very good fuel quality.

If you have bimmerlink and a OBD, you can measure the fuel quality realtime and see what type of power it is pulling. Or also use ISTA+ to measure your fuel quality over time.

Hmm I could get bimmerlink easily enough and see what happens.

[Nezil]

Originally Posted by cookiesowns

Once you do a vehicle scan, click on the DME module and use "call ecu functions" then there should be some diagnostics method in there to get the fuel quality. If it's not there, then just search for fuel quality and there should be a measures plan to call up the information.

I did check this in the parking lot at work this evening, and got as far as Call ECU Functions for the DMI (I assume that was the correct ECU). I couldn't find anything in there about fuel quality.

What is it in Bimmerlink that tells you fuel quality?

In what way is fuel quality quantified? Are you just suggesting to look at timing corrections, because we get this from the BM3 logs anyway don't we?

[cookiesowns]

Originally Posted by Nezil

I did check this in the parking lot at work this evening, and got as far as Call ECU Functions for the DMI (I assume that was the correct ECU). I couldn't find anything in there about fuel quality.

What is it in Bimmerlink that tells you fuel quality?

In what way is fuel quality quantified? Are you just suggesting to look at timing corrections, because we get this from the BM3 logs anyway don't we?

There's quite a few parameters that the DME looks for in fuel quality. Timing correction overtimes, calculated fuel density. Unfortunately I still haven't found a factory bosch function document for the MEVD172G DME's ( cost several thousand dollars ) so I can't tell you specifically.

In bimmerlink there is a PID to measure the DME reported fuel multiplier. Anything less than 1 would mean less than perfect fuel quality. On shell VPower+ Nitro 91 here in so cal, I generally average about .98 to .99 on the stock tune, with occasional 1.0+

I'm not at my car right now and bimmer link doesn't allow you to view the saved dashboard settings until you are connected. I'll chime back here, along with ISTA screenshots when i work on it tomorrow.

[Nezil]

Originally Posted by cookiesowns

There's quite a few parameters that the DME looks for in fuel quality. Timing correction overtimes, calculated fuel density. Unfortunately I still haven't found a factory bosch function document for the MEVD172G DME's ( cost several thousand dollars ) so I can't tell you specifically.

In bimmerlink there is a PID to measure the DME reported fuel multiplier. Anything less than 1 would mean less than perfect fuel quality. On shell VPower+ Nitro 91 here in so cal, I generally average about .98 to .99 on the stock tune, with occasional 1.0+

I'm not at my car right now and bimmer link doesn't allow you to view the saved dashboard settings until you are connected. I'll chime back here, along with ISTA screenshots when i work on it tomorrow.

Thanks very much, this is REALLY helpful.

I'm writing an email now to VP Racing, in case they can shed some light on the subject. They obviously know their fuel!

[akkando]

Originally Posted by cookiesowns

There's quite a few parameters that the DME looks for in fuel quality. Timing correction overtimes, calculated fuel density. Unfortunately I still haven't found a factory bosch function document for the MEVD172G DME's ( cost several thousand dollars ) so I can't tell you specifically.

In bimmerlink there is a PID to measure the DME reported fuel multiplier. Anything less than 1 would mean less than perfect fuel quality. On shell VPower+ Nitro 91 here in so cal, I generally average about .98 to .99 on the stock tune, with occasional 1.0+

I'm not at my car right now and bimmer link doesn't allow you to view the saved dashboard settings until you are connected. I'll chime back here, along with ISTA screenshots when i work on it tomorrow.

I have bimmerlink, can you tell me where to find this?

[Mdkcrf250r]

You’re threatening a lawsuit against the oil companies (who have a team of lawyers, good luck) because someone on the internet said you “might” have 88 octane fuel? Do you even hear yourself? I’d venture out on a limb and guess the car would run fine on 87 so long as you’re not tracking it exclusively.