Old BMW and SI-1 -what should I expect?

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I just bought 3 bottles of Redline SI-1 and plan to use one bottle on a full tank and then try a SI-1 maintaince treatment in my 95 BMW 525i. Previously used UCL with the only result really being a possibly smoother engine.

What should I expect with SI-1? FYI, I have completed three ARX treatments and use Chevron 93 octane gas. Engine should be fairly clean. TIA
 
Engine should be in excellent shape. Plugs are about 12,000 miles old. Air filter less than 2,000 miles old All six coils are original but with new connectors last year. Able th get 28-30 mpg at 65-70 mph
 
It makes my CV much more "punchy" after a treatment. The engine seems to labor less on heavy loads like climbing a steep grade above 80mph.
 
That Redline is a very good cleaner.
It will clean your injectors, valves, and combustion chambers.
When a car has injectors that flow the same with good patterns, it runs better and more efficiently.
You shouldn't need it with every tank, though.
 
Sure seems to run smoother and stronger with entire bottle SI-1 in about 14 gallons of 93 octane Chevron Supreme. Of course it could just be the ole "i want it to be so" effect. :)
 
SI-1 is a very good product and you probably do notice a difference. I personally think the 3 oz per tank maintenance dose is a waste of money. It uses some of the same chemistry as the Gumout REGANE and it has a residual effect. Adding a full bottle every 4-5K should keep things nice and clean.
 
Johnny - I agree Gumout Regane and SI-1 are excellent products that utilize PolyEthylAmine (PEA) as they key ingredient, but I do not see how either product has any "residual effect".

How do you see this happening?
 
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I wish I still had access to the Gumout tech manual. I'm not sure if it's an added chemical or the PEA itself, but there is something chemically in there that under heat puts a light coating on the valves to retard the deposits from reforming. What ever it is last for about 4K. It may well be the PEA as Techron and the Amsoil PI will do the same thing.

It will probably take a chemical engineer that knows a lot about fuel additives to give a better explanation than I can, but that is what I was told at both a Gumout and Chevron tech school years ago.

Maybe the fact that the SI-1 has a synthetic Upper Cylinder Lubricant in it has something to do with their recommendation. The REGANE and Techron do not use UCL's.
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Redline injector cleaner is certified as capable of meeting BMW's "Clean Test". It's one of the best cleaners out there.

I've not used anything better.
 
Originally Posted By: Vspec
In sheer cleaning power SI-1 vs Amsoil PI. What say you?


I'd put my money on SI-1 for cleaning power only.

The PI seems to tame a fuel's punch somehow. It's an interesting product if you want to tame a wild engine. ??
 
I just went to store, and picked up a bottle of SI-1
so far so good, but I use shell vpower 93, or BP 93 so the fuel system cant be to bad.
 
Originally Posted By: mjfx
I dont wanna tame my engine I want it to go buck wild



Octane booster might help with that. :)
 
Originally Posted By: rg200amp
I just went to store, and picked up a bottle of SI-1
so far so good, but I use shell vpower 93, or BP 93 so the fuel system cant be to bad.


These powerful cleaners are most useful when you buy an older car with questionable maintenance history.

My 93 Trooper is the perfect test bed for trying out new cure-alls.
 
Russell, since you have a BMW - I assume it has the OBC - try this for a while: measure your fuel mileage for each tank using the OBC, and also calculate it using gallons-per-mile-driven at each fill-up. On my car I have noticed that the difference between the two figures is a very good indication of injector cleanliness. That makes sense, since it seems reasonable that a dirty injector would deliver a bit less fuel than the computer thinks it will be delivering.

When not using any cleaner in my car the difference between those two numbers drifts up to about 3% or a little more - about a 1mpg - 1.5mpg offset. I have never seen it consistently above that range.

Using a bottle of Regane or SI-1 will usually bring it right back down to a perfect match (varying between ~1% and ~-1% difference).

Recently I have been experimenting with smaller amounts of SI-1 in each tank. Currently I am using 1oz per fill-up, and it seems to be keeping the injectors in that -1% - 1% range.

I think Johnny is onto something, too. The SI-1 advertises itself as a top-end lube as well as a cleaner. I have seen that using a top-end lube will keep a light coating of oil on the valves, and it makes sense that it would help to prevent additional desposits from re-forming:

DSCN1776.jpg


The above photo was taken when using 4oz/10gal MMO in my car - the recommended dose.

I am currently using 2oz MMO in each tank along with the SI-1 and believe it is helpful. The combination adds about $0.90 per fill-up. Not totally inconsequential, but less than the difference between top-tier and other fuel, for example. The SI-1 component is equivalent to using a whole bottle every 6k miles or so. I have little transparent travel-size shampoo bottles that I pre-fill with the right mix for each fill-up.

My car, if you don't recall, is an E30 325i, with the older two-valve M20 engine.
 
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