Fuel additive

[odo]

My '01, 4.4i has been running poorly for a month or so. The service light came on and my mechanic read the code. I can't remember the number, but the problem was on one side of engine in fuel system. I had been running 89 octane vs recomended 91, and geerally bought the cheapest I could find. Mech suggested that I treat the fuel with techron (that is only kind of additive he recommends for BMW's) for a few tank fulls to see if that cleaned up the system. I have been buying 93 octane at Chevron AND adding more techron, but haven't noticed any change yet. I found some Techron Pro-guard fuel injector cleaner in my garage. Can anyone tell me if it is OK to use that in my BMW. I'm hoping it might speed up the fuel system clean up.
One more question: will the lower octane (89 vs 91) cause me any problems, or just slightly reduced performance?

[primetime]

Use the techron about 3 times. Use it once everytime you fill up. You should notice after awhile. Also the lower octane is a little dirtier too. It just isn't as clean to put it in simple terms. Performace will drop off slightly, and you may have an engine knock from time to time. Use premium all the time, Try to use Shell gasoline if possible..

[JCL]

Agree with trying the Techron, but if you just have an old bottle in your garage I would go buy some, new and in a sealed bottle.

The 89 octane rating won't hurt your car at all. The gasoline is the same spec, and so is as clean as the premium. You will not have any knock. However, if it was cheap gas it may have had fewer additives (cleaners) than premium from the same station, and that could have contributed to fuel system deposits over time. If so, the Techron treatment can help.

I try to stay away from Shell, but to each his own.

[primetime]

JCL what gasoline station do you use? Have you had a bad experience with Shell?

[odo]

Thanks for the replys, guys. The "Techron Pro-guard fuel injector cleaner" is different from the Techron additive. I don't know what the difference is or if the Pro-Guard may be too harsh for a BMW and cause more problems down the road. The Pro-guard was in a sealed bottle. I bought it a few years ago, moved and finally unpacked some boxes recently and found it. Thanks

[JCL]

Originally Posted by primetime

JCL what gasoline station do you use? Have you had a bad experience with Shell?

My first choice is Chevron. Second choice is Imperial (Esso). I use Petrocanada if I have to. I used to really like Shell, but after a few tanks that were noticably different I dropped it. It is a challenge not using Shell, since the company I work at has a deal with Shell, and we get issued Shell fuel cards. I can use the card elsewhere, but every now and then I get a reminder from our purchasing department that they want us to build volume at Shell retailers.

[JCL]

Originally Posted by odo

Thanks for the replys, guys. The "Techron Pro-guard fuel injector cleaner" is different from the Techron additive. I don't know what the difference is or if the Pro-Guard may be too harsh for a BMW and cause more problems down the road. The Pro-guard was in a sealed bottle. I bought it a few years ago, moved and finally unpacked some boxes recently and found it. Thanks

I think you are safe using the Pro-guard cleaner, but I would recommend you get a bottle of the Techron cleaner instead. Chevron lists them as two distinct products.

Use as directed; problems usually come from using heavier concentrations than the product was designed for.

[motordavid]

The ProGuard stuff may just be marketing or, it may be good...
I know it does have some Techron in it, as the bottle states, but
not in the concentration that "std" Techron has, though real
analysis is tough.

It probably has other things too, for fuel injector cleaning.
I wouldn't think it could hurt, just not as concetrated as Techron.
Anecdotally, many car boards report using it, fwiw.

Otoh, nothing additive-wise, may alleviate or "correct" your code,
though.
GL,mD

[motordavid]

JCL, posting on top of each other, lol!
I was off reading up on Techron, in mid-post, ;>)

[X5rolls]

You have a great vehicle - I'd try treating it correctly by getting better and recommended octane gas.

Originally Posted by odo

I had been running 89 octane vs recomended 91, and geerally bought the cheapest I could find.