CORSASCHNELL

Do you use any type of additives in your cars? Fuel additives like Techron for fuel system cleaning, Zmax, etc. oil additives for additional lubrication, etc?

Any good, bad or indifferent results?

Charolastra

No. My trusted mechanics (both for my VW and my Porsche) told me these were largely worthless and to not waste my money on them. Unless you're having problems with misfires or rough idling, it's unlikely that anything's dirty enough to worry about. Gasolines have enough detergents in them these days that dirty fuel systems rarely are a problem.

With that said, if you have a very high mileage car (~100k+), it may make sense to consider a more thorough fuel induction cleaning (which normally costs a lot more than a can of Techron, 44k, etc.). The difference there is, they are probably hooking your car up to a machine that pumps a pretty strong solvent into your car. If you do go this route, make sure to:

1. Really work out the engine when you are driving it afterwards, just to ensure you blow all the gunk out (else risk fouled plugs and misfires), and

2. Change the fuel filter while you're at it, just to REALLY make sure you're getting all the gunk out.

Spokane5150

You run Super Unleaded which has injector cleaners and is formulated to keep your fuel system clean.

Skibum

Techron.. when needed followed by an oil change.

sullivas

Stabil Ethanol treatment. I heard some things. Hey it can't hurt.

kosmo

this

Harvey in FL

Techron...always before every 3.5K oil change.

hakaida702

I almost always use top tier gas except when I go to costco (they have a gas called kirkland signature with clean power additives) so I figured that additives are worthless. Maybe I'll check out techron since a few of you feel that it is worth buying. I'll see if costco has it first.

CORSASCHNELL

I add a can of Techron every month although always fill up with Top Tier gas from Shell. There is also a Fuel System Cleaning kit from 3M (cost $50) which includes an additive for fuel tank, MAF sensor cleaner and injector cleaner, but never tried it before.

I have used Zmax in my AMG before and engine runs noticeably smoother but fades away after 1,000 mile or so (or maybe I just get used to it), but never dared to use it for the 911. They call it a micro or nano lubricant and is supposed to penetrate into metal surfaces for lower friction levels.

kosmo

techron monthly is too much. Chevron says 2x a year.

costco carries fuel injector cleaner w/ techron. thats different than the pure techron stuff.

jhbrennan

That's what I've been told too...plus it's recommended you change the oil after a Techron treatment.

CORSASCHNELL

Theoretically all the dissolved soot and carbon deposits should burn up in the combustion chamber and come out of your exhaust pipes, however some will get into the oil, so I think an oil change after using Techron is a good idea.

Not sure if it is my imagination or not, but my car runs stronger with Techron additive in the tank, just feels more responsive with a bit more power.

GSIRM3

Anyone notice more soot on back of their 997.2 when running Shell V-Power? My car is white, so the soot is more noticeable, but I definitely get more soot with V-Power.

Macster

The back of the car gets dirty with a lot of stuff from the fact that area of the car experiences low pressure and dust and whatever that is stirred as the car moves down the road though a parking lot and so on kind of floats around.

Watch wind eddying around a building and the trash that can collect in the low pressure area as the wind curls around the building. I've seen leaves and paper and such just hang almost like they are suspended by fine wires for some time.

Besides you do not know if that is soot from your car or that of other vehicles on the road. I mean look at the exhaust of any Porsche 911 vs. say the exhaust of a big rig. Where do you think the overwhelming majority of soot on the road way comes from?

When people mention sooty or exhaust tip build up I have to point out there are 2 converters between the combustion chambers and the exhaust tips.

Soot or tip colors are more a reflection of what's going on in the converters rather than the engine unless the engine is showing/exhibiting clear signs of distress.

Then no one is going to care what the exhaust tips look like, how much soot is at the back of the car but what symptoms is the engine manifesting what error codes are behind the CEL, etc.

In your car's case, with no CEL, no engine misbehavior, with a possible change in gas blend (some areas have seasonal blends and fall starting in a day or so), gas possibly of questionable freshness, a change in driving style due to traffic changes arising from say a slower commute/drive due to heavier traffic now that school is back in session and in some areas of the country -- in the bay area anyhow -- traffic has gotten worse (as thank goodness more people are working) I'd say you need to spend less time looking the back of your car and more time looking through the windshield of your car.

Sincerely,

Macster.

GSIRM3

Nope, it is definitely soot from my car. Soot from the DFI engines is common. I had two previous 997.1 cars with no soot issues. I have some soot, as I think all 997.2 owners do, with any gas. But there is no doubt that it is worse with V-Power.

Thanks for the lecture on needing to spend more time looking through the windshield than looking at the back of the car. I don't recall saying that I spend much time looking at the back of the car, nor did I say I was concerned, or thought I had a problem with the car. The soot is pretty easy to see when I wash my car. I simply asked if anyone had noticed more soot when using Shell V-Power. Thanks again for the lecture.