i would just use chevron premium. they all have techron in it...actually all the top tier fuels have similar addiatives just chevron is the most famous for it.

Here's a list of top tier fuels..you don't have to use cheveron..any fuel brand on the list will provide similar results.

http://www.toptiergas.com/index.html

 

Just run Chevron Premium fuel, it comes predosed with Techron - You only have to use Techron concentrate if you have a problem.

As Mike says above - you can use any top tier fuel. Techron is just a little better. The Techron system is proprietary to Chevron/Texaco/Caltex and produced by Chevron's additive division Oronite. It carries the wording "Unsurpassed" in it's advertising globally and no other oil company has been able to successfully challenge that. It is still the best product on the market for clean up & keep clean of the inlet system.

 

Not exactly, have you seen a bent valve on a M271 head?

The valve clearance wasn't spec'd right on the M271 and carbon build up can cause them to stick, then bend, and slap a piston.

My mechanic has no clue why a piston failed on my car, yet its the second M271 he's seen it happen on. My car should have never been running rich, in fact due to the cam sensor leak that was mis-diagnosed by the dealer for over a year, it was running rich. Knock is a suspected problem, since the oil leaked into the knock sensor cable and it actually burned through, so its debatable how well the knock sensor was working.

 

Now you are really talking There is nothing wrong with valve to guide clearance on the M271 - BMW & Opel run even tighter clearances. Build up on a valve tulip is not a combustion chamber deposit (carbon) - it's an inlet system deposit and it is caused by multigrade engine oil leaking down the guide & burning on to the valve tulip. Multigrade oils contain VI improver (milled polymer - or in basic terms plastic). It is the VI improver that builds up on the valve tulip & can ultimately cause a valve to hang open in a close tolerance engine. This is due to using cheap non additised fuel that does not clean the valve tulips. Premium fuels from reputable major oilcos that contain additives such as Techron will prevent this completely. The problem can be exacerbated by worn valve stem seals and poor engine oils &, in fact, wide tolerances between valve stem & guide.

The normal failure mode on M271 heads is erosion of the combustion chamber leading to hot spots, uncontrolled combustion (knocking, pinging, dieseling) - & misfires. Not bent valves!

I think there is little doubt that your piston failure relates to the knock sensor being inoperative - not retarding the timing at the onset of knock with resultant damage. You have already admitted to driving the car hard & using crap fuel. You say in other threads that the O2 sensors were adversely effected by oil impregnation of the harness due to leaking cam sensors. This could have caused either lean or rich running.

So we have two possible scenarios:

Running lean = higher than normal temperatures that can ultimately lead to piston failures because it aggravates knock.

Running rich = greater combustion chamber desosits - deposits become incandescent - leading to uncontrolled combustion or knocking with resultant damage. Exacerbated by inoperative knock sensor.

Endeavour to control your belligerence