Originally Posted By: Scum_Frog
Does it still make sense to use a Fuel System Cleaner over X amount of miles/kms if one constantly uses a Top Tier gas such as Shell or Esso as these petrol's are suppose to loaded with detergents in the first place?
Your thoughts......
The problem is the amount of detergent in the fuel (only V power has a high level of detergents in the Shell fuels) but it also contains 10% ethanol.
Ethanol is hygroscopic and corrosive and even more so as the moisture content get higher.
Its a catch 22, the additives in the fuel clean or keep deposits to a minimum but at the same time the ethanol component of the fuel is corroding things, as fuel ages it also creates varnish that it cannot clean itself.
Its true, gasoline is a solvent but it is unable to remove its own varnish deposits without an additive.
Some injectors are more prone to deposit and varnish than others, some injectors spray a lot of fuel and have fairly large openings, these are usually more tolerant than the ones with a very fine spray and opening so small that almost any particle can either clog them or throw the pattern or flow rate off.
This is very engine specific. A large engine doesn’t necessarily mean big flow, some small engines have injectors that flow like a garden hose.
This get even more complicated when dealing with injectors in multi valve heads, they use 2 distinct streams, one for each intake valve. These are more prone to issues than most others.
Running top tier really can help and the use of an OTC additive is probably only needed once in a while say once a year or 10K. Multi valve engines are probably better using it every 5K.
The problem is once the deposits form its very difficult to get rid of them without taking them off the engine.
There is no real yes or not answer, its variable. I know my cars and the injectors in them, one needs nothing and would almost take a rubber stopper to clog the injectors, the others are a bit problematic and benefit a great deal from a regular dose of Techron or Redline SI-1 regardless of the fuel used.
I will go out on a limb and aint with a very broad brush and say, if you have older style metal body injectors especially Bosch pintel styles or multi valve Ford, BMW, Siemens/Deka commonly found in some Chrysler products or older GM Multec or spiders you should consider using an additive more often.
This is by no means even a half complete list.
