Fuel quality and oil life

[MGBV8]

In UK I use Shell Optimax which is 98 Octane highest avaiable, sandard fuel is 95 Octane. LPG is I think 101 Octance and is often used a duel fuel. Just wondered whether octane had any effect on oil.

 

[Quattro Pete]

quote:

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Originally posted by TallPaul:
Very interesting it mentions fuel quality. I don't recall that ever being mentioned at BIOTG regarding effects on oil, but BIOTG member Callisa (rarely seen here, but frequent at NORIA), who is from Germany and I believe is with an oil company there, told me at NORIA that fuel quality is an important factor in attaining the long OCIs typical in western Europe.

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I mentioned this in other posts about Castrol SLX 0w30 (GC). In Poland, there was a widespread issue of engine oil sludge on Toyota vvt engines that used SLX. Castrol's response was that it was due to the reaction of this oil with poor quality of fuel sold over here. This is when Castrol updated the SLX and created SLX LongTec which is sold here (and what I currently run in my 1.8T). Not sure what they did to it to prevent sludge caused by poor quality fuel though.

On the other hand, if the fuel in the US was poor quality, you'd probably see SLX sludging your engines as well. I don't think I've seen any proof of that, but the again, not too many BITOG members run it @ 10K mile OCI or more like they do in Europe. Also, living in the US for over 10 years, I never experienced any "bad fuel", although I always used brand-name gas stations.

I don't trust gas here in Poland. I haven't experience any apparent issues yet, but if I could get my hands on Fuel Power, I'd use it.

 

[Quattro Pete]

quote:

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Originally posted by John_E:
as far as I know, 1.8Ts driven in Europe DO NOT DIE OF SLUDGE,

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1.8Ts driven in Europe also do not get fed cheap mineral oil, like most of the US Audi/VW dealers have been doing for years.

You buy a 1.8T in Europe, and you have to service it at a dealership in order not to lose your warranty. And the dealership uses strictly high quality synthetics. Granted you pay an arm and a leg for it (a typical oil change at an Audi dealer costs about 150 USD over here), but as a result you're not likely to have any sludge-related issues.

 

[John_E]

quote:

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Originally posted by Quattro Pete:
1.8Ts driven in Europe also do not get fed cheap mineral oil, like most of the US Audi/VW dealers have been doing for years.

... And the dealership uses strictly high quality synthetics. Granted you pay an arm and a leg for it (a typical oil change at an Audi dealer costs about 150 USD over here), but as a result you're not likely to have any sludge-related issues.

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Now that I'm using Mobil 1 0W-40, I suppose I should probably get a used oil analysis to see whether I should keep my 3 to 3.5K mile OCI, chosen because of urban driving, or try for a "by the book" 5K.

 

[Quattro Pete]

I think you'll be perfectly fine with 5K mile OCIs.

 

[JohnnyG]

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I need practical advice, such as which brands of gasoline to use (Chevron? Union 76? the new Shell?) or to avoid, and which fuel system additives, if any, to use (BG 44K?), and how often.

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I don't think many people comprehend the gasoline supply chain in the USA. Gasoline is ALWAYS produced locally...find the nearest refinery and you'll find the source of ALL the gasoline in that geographic area...REGARDLESS of brand. What differentiates Chevron from Union 76, from Exxon? The ADDITIVES. In other words, if a contaminant is present in a geographic area, in the "base gasoline" it will be present in all brands in the same quantities in that area. Be careful living on the coast..your gasoline is most likely produced and refined off-shore in places like Venezuela or Aruba and imported as a finished product. (Who ya gonna call?) Now, from my expierience, Exxon adds the most detergents to their gasoline...but the question then becomes how much is too much? What happens when three times the recommended amount of BASF APDGM4000 (additive) burns in a combustion chamber? What goes into the oil then? Right now, Speedway filters their gasoline through a 2 micron filter and adds the same detergent as Chevron (techron), so which gas is better? That's determined by the refinery, which makes BOTH brands identically.
There is a LOT of brand loyalty in the US right now...most of it is not based on facts. This sort of reminds me of why this forum talks about engine oil...most of the time is spent dispelling rumors, old wives tales, and stories from the WalMart guy.