[khp3655]

I poke around car forums quite a bit and have seen many debates about octane and gas, usually about trying to save money using 87 octane. In my Z4 s30, it is 90 or better, which usually means 91. I thought that was enough to be doing right by my engine.

Although I had seen it mentioned a couple of times over the years, I just learned that Top Tier Gas is a thing, and it sounds like using it makes a difference. A number of articles came out recently about an AAA study and showed just how much less carbon build up there was in engines that used Top Tier Gas. Now that I know where to look and the symbol to look for, much more Top Tier Gas in is my future.

Is the idea of using Top Tier Gas (vs just using the proper octane gas) well-known? As someone who enjoys cars, travel, and learning, I was genuinely surprised that I had not known about this standard before.

[jzeiler4]

I became aware of Top Tier gas twenty years ago when GM, BMW, Honda and Toyota collaborated on setting the new standard. It is the only gas I buy unless there is none available.

[ctcarbonari]

Full Disclosure - I only became aware about 3 years ago when I got my "new-to-me" bimmer and started looking into it. Before then, I ignorantly believed it was a myth and filled my tank with whatever was convienent (and usually cheap).

[DanG]

I have been using top tier for years.

[BlkGS]

Top tier gas just has extra cleaners than the minimum required by federal law. It's mainly a marketing gimmick, where you run the test everyone passes, and then pay the licensing fee.

You're not gonna get anything out of it more than you would by adding a bottle of techron or other PEA based cleaner in a tank once a year. You'll get no benefit from it in a Direct Injection motor.

[Ugly Kar]

Ugh! Only 4 threads down and 17 pages.
https://g87.bimmerpost.com/forums/sh....php?t=1571574

[FrankMstein]

BP fell off last year.

Wait until you find out what LL-04, A40, MB228 is.

[tturedraider]

Around these parts Top Tier gas is pretty well known and often cussed and discussed. Even here there are still a few yahoos who believe it’s a myth.

[RockCrusher]

Originally Posted by khp3655

I poke around car forums quite a bit and have seen many debates about octane and gas, usually about trying to save money using 87 octane. In my Z4 s30, it is 90 or better, which usually means 91. I thought that was enough to be doing right by my engine.

Although I had seen it mentioned a couple of times over the years, I just learned that Top Tier Gas is a thing, and it sounds like using it makes a difference. A number of articles came out recently about an AAA study and showed just how much less carbon build up there was in engines that used Top Tier Gas. Now that I know where to look and the symbol to look for, much more Top Tier Gas in is my future.

Is the idea of using Top Tier Gas (vs just using the proper octane gas) well-known? As someone who enjoys cars, travel, and learning, I was genuinely surprised that I had not known about this standard before.

It is important to use the grade of octane called for by BMW.

As for Top Tier fuel I refer you to your car's owners manual.

A paste from my M2's owners manual:

The use of poor-quality fuels may result in harmful engine deposits or damage. Additionally, problems relating to drivability, starting and stalling, especially under certain environmental conditions such as high ambient temperature and high altitude, may occur.

If drivability problems are encountered, we recommend switching to a high quality gasoline brand and a higher octane grade — AKI number — for a few tank fills. To avoid harmful engine deposits, it is highly recommended to purchase gasoline from Top Tier retailers.

Failure to comply with these recommendations may result in the need for additional maintenance.

[RockCrusher]

Originally Posted by BlkGS

Top tier gas just has extra cleaners than the minimum required by federal law. It's mainly a marketing gimmick, where you run the test everyone passes, and then pay the licensing fee.

You're not gonna get anything out of it more than you would by adding a bottle of techron or other PEA based cleaner in a tank once a year. You'll get no benefit from it in a Direct Injection motor.

When I have had my 2 230s and one M2 in for service, this is used or a bottle is given to me to use:

https://www.getbmwparts.com/oem-part...ve-83195a07750

By my SA I was told the use of that additive was recommended by the factory. I also note both my 230s and my M2 are direct injection engines.

(I don't wish to get into an argument but my info is Techron at least can benefit a DI engine.)

At any rate I have used the BMW fuel additive or what I prefer is I decline the BMW additive and pick up a bottle of Techron from the local auto parts store.

[DanG]

Originally Posted by RockCrusher

When I have had my 2 230s and one M2 in for service, this is used or a bottle is given to me to use:

https://www.getbmwparts.com/oem-part...ve-83195a07750

By my SA I was told the use of that additive was recommended by the factory. I also note both my 230s and my M2 are direct injection engines.

(I don't wish to get into an argument but my info is Techron at least can benefit a DI engine.)

At any rate I have used the BMW fuel additive or what I prefer is I decline the BMW additive and pick up a bottle of Techron from the local auto parts store.

If you use a Top Tier gas you don’t need an additional additive.

[BlkGS]

In a DI motor the fuel is injected directly into the combustion chamber when needed. It doesn't have any time to do any cleaning unless it somehow survives the combustion event.

In port I jected motors the fuel is injected in the head, so it flows over the valves and cleans them of any carbon buildup. That where top tier gas or an additove can help.

[jkoral]

Refer to BMW SI B13 02 06 - https://static.nhtsa.gov/odi/tsbs/20...52346-9999.pdf

I've known about this for many years, but filling up on the NYS Thruway this weekend, and it was the first time I noticed the Top Tier sticker on the pump:

[NYG]

Shell Master Race

[jdl5068]

Originally Posted by NYG

Shell Master Race

This right here, I am in a position that handles all the big company products and when you see which ones accept the specs of the gasolines as a base and then still spec them up you know. Shell is the highest level to start right out of the gate without even adding before the tankers are sent out to the stations.

[FrankMstein]

Originally Posted by jdl5068

This right here, I am in a position that handles all the big company products and when you see which ones accept the specs of the gasolines as a base and then still spec them up you know. Shell is the highest level to start right out of the gate without even adding before the tankers are sent out to the stations.

Agreed. Same with base oils. David70 might disagree with you. He thinks it's all the same and "is in the industry" too.

Some here believe it's all the same since it comes from the same refinery/pipeline. Somehow the tinfoil hat is too tight.

[FrankMstein]

Originally Posted by BlkGS

In a DI motor the fuel is injected directly into the combustion chamber when needed. It doesn't have any time to do any cleaning unless it somehow survives the combustion event.

In port I jected motors the fuel is injected in the head, so it flows over the valves and cleans them of any carbon buildup. That where top tier gas or an additove can help.

Are you forgetting the injectors?

[BlkGS]

Originally Posted by FrankMstein

Are you forgetting the injectors?

Somewhat, but any modern fuel should be sufficient to keep injectors clean on a car driven regularly.

For collector cars that will go through gas over a matter of years, I'd look for the best E0 fuel incould find and go for it. For an every day driver, fresh fuel from a station with high turnover is better IMO.

[Ximian]

Where the Top Tier label is very helpful is gas stations that aren't a big chain. There's is a cheap looking gas station called "Super Gas" that I drive by occasionally and it's 30 cents cheaper per gallon than anyone else. It doesn't have a Top Tier sticker at the pumps. How confident are you that it's going to have good quality fuel?

I don't even look for the sticker when I go to fill up with Shell 93 octane because it'll be even better than most Top Tier fuel. Luckily the gas station is close to me and cheaper than chains.

Originally Posted by FrankMstein

Some here believe it's all the same since it comes from the same refinery/pipeline. Somehow the tinfoil hat is too tight.

The anecdote of "I saw the same tanker fill up the BP gas station after it filled up the Shell gas station" that I've never seen myself. I could believe it with one of the non-oil company branded stations, but that's not a guarantee they'll have the same fuel each week as they could be shopping around that often.

[RockCrusher]

Originally Posted by BlkGS

In a DI motor the fuel is injected directly into the combustion chamber when needed. It doesn't have any time to do any cleaning unless it somehow survives the combustion event.

In port I jected motors the fuel is injected in the head, so it flows over the valves and cleans them of any carbon buildup. That where top tier gas or an additove can help.

Techron does survive combustion. During combustion it is heated to its vapor phase then when as a vapor it comes into contact with cooler combustion surfaces reverts back to its liquid phase and in doing so works to cleanse the surfaces it comes in contact with.

This works in either port or direct injection engines.

How it works in direct injection engines is the DI engine is designed (using variable valve timing and opening the intake valve earlier) under some operating conditions to encourage some back flow of exhaust gases into the intake port past the opening intake valve(s). (Essentially exhaust gas recirculation without all the EGR hardware.) The purpose of this back flow is to slightly pollute the incoming air with exhaust gas to lower combustion temperature and reduce NOx emissions.

This works. NOx emissions are lower than they would be otherwise.

But the downside is the backward flow of exhaust gas results in some deposits collecting on the back of the intake valves but Techron now in vapor form in the exhaust gases Techron works to remove the deposits.

Unfortunately only Chevron gasoline comes treated with Techron.

However, Techron can be added to any gasoline that doesn't come with it.

As I have mentioned before for some time now my local BMW service has been adding a BMW labeled Techron additive to my car's gas tank -- this after putting in fresh oil during an oil/filter service -- or handing me a bottle of it when I settle up and collect the key to my car.

With the bottle I can use the Techron when I think it best. "Best" is I've been told is a few hundred miles prior to an oil/filter service.

[OGOverkill]

there is a local shop who often does some local gas tests and the results are quite surprising

[BlkGS]

Originally Posted by RockCrusher

Techron does survive combustion. During combustion it is heated to its vapor phase then when as a vapor it comes into contact with cooler combustion surfaces reverts back to its liquid phase and in doing so works to cleanse the surfaces it comes in contact with.

This works in either port or direct injection engines.

How it works in direct injection engines is the DI engine is designed (using variable valve timing and opening the intake valve earlier) under some operating conditions to encourage some back flow of exhaust gases into the intake port past the opening intake valve(s). (Essentially exhaust gas recirculation without all the EGR hardware.) The purpose of this back flow is to slightly pollute the incoming air with exhaust gas to lower combustion temperature and reduce NOx emissions.

This works. NOx emissions are lower than they would be otherwise.

But the downside is the backward flow of exhaust gas results in some deposits collecting on the back of the intake valves but Techron now in vapor form in the exhaust gases Techron works to remove the deposits.

Unfortunately only Chevron gasoline comes treated with Techron.

However, Techron can be added to any gasoline that doesn't come with it.

As I have mentioned before for some time now my local BMW service has been adding a BMW labeled Techron additive to my car's gas tank -- this after putting in fresh oil during an oil/filter service -- or handing me a bottle of it when I settle up and collect the key to my car.

With the bottle I can use the Techron when I think it best. "Best" is I've been told is a few hundred miles prior to an oil/filter service.

Gumout uses PEA in some of their formulas (like Techron) and offers mixed perspectives on it. They claim it "survives the harsh environment of the combustion chamber" but also say that to clean a DI vehicle it has to be slowly added via an intake manifold vacuum line.