I agree with pcb5. i've had far less expensive/lower quality cars that were far less "sensitive" than these BMW's. And the TOTALLY weird thing is, I truly love this car! Maybe, just maybe, the manufacturer was hoping/looking for just this very thing; totally advise against any and all additives so that by the 100k mark, a nearly total engine revamp will be necessary. Now for the record, I do not work for any company that produces any additives. As a matter of fact, I'm in between jobs, lol!

 

I feel like if I look at it wrong, it's gonna break! BMW=BustMyWallet!!!!!

 

I wasn't saying putting complete faith in what BMW advises. Every manufacturer makes a similar statement about using only their official/OEM fluids, it's mostly i think to avoid liability for people putting stupid stuff in their cars and then suing the manufacturer because "you didn't tell me I couldn't!". in this case, the fact that they say the vehicle doesn't need them is just one more reason, on top of the others I mentioned.

 

A better question might be "why use oil additives?". Find some empirical (not marketing, or anecdotal) evidence to support dumping who-knows-what into your engine.

Last I checked the solution for worn valve guides is new valve guides.

Macmark, a reason for "cheaper" engines not being as sensitive might be that they're less on the edge. I can put 5-year old gas in my '50s farm tractor and it's perfectly capable of running at full power on what amounts to varnish. I wouldn't dare do that in an engine of roughly the same displacement that puts out 600% more power.

 

Got it. I was trying to open up a healthy debate, by raising a legitimate point. At least it made us go "hmmmmm"...

 

Good sense in those comments. The net is full of reports from independent test labs showing that these well-advertised additives and aftermarket products generally produce no or marginal results, and many are actually detrimental to performance and engine life.
So why do people believe in snake-oils? Sparkly advertising and the diff in price between a can of oil thickener and a valve job have a great deal to do with it.

 

ZDDP is a legitimate oil additive used to reduce wear. Many of your FE "Fuel Economy" oils have low levels of phosphorous and zinc. Ditto for the Extended Performance oils that advertise 15,000 miles.

However, ZDDP, will reduce your MPG's, and some claim that at levels of 1750+ they can hurt your catalytic converter.

Mobil 1 0W-40 has a ZDDP score of 1000 Zinc and 1100 Phosphorous. Many FE oils run around 650 and 750.

This ZDDP additive takes it up to the 1700 level but not beyond, so it should be safe for your CAT, plus provide the highest level of wear protection. MPGs will drop.

ZDDPlus™ - ZDDP for Classic, Muscle Cars & More

You can obtain the same result by using 15w-50 racing oil. Or you could use the cheapest 100% synthetic oil and add the ZDDP to obtain superb wear protection.

Myself, I'm using Mobil 1 0W-40 and that's that.

 

FWIW, I have an '87 325i with an OEM catalyst, and I've been using M1 15w-50 in it for years (which has an elevated ZDDP level for older style engines, such as the flat tappet M20). I have never had emissions issues with that car.

I'm not quite sure how they affect MPG. Could you elaborate?

Also, Valvoline VR1 20W-50 has lots of ZDDP.

 

Yes, the ZDDP creates a greater film thickness between moving parts. This causes greater friction that reduces MPGs. But I will trade MPGs for wear protection any day.

If you look at any of the oils that market themselves as first, and foremost, increasing fuel economy, and lower emissions, you will find those are the same oils with much lower ZDDP levels.

I'm not talking about major MPG loss, as it mostly pertains to higher emissions levels, as the Green Movement is the primary driver for reduced ZDDP.

15w-50 is fine provided you're in a warm winter climate. If you're up North, I think a 0W weight is much better during the winter months

 

ZDDP is zinc which is bad for human consumption and everything else.Almost nothing can replace it on flat tappit older American Muscle.I tried everything on worn valve seals.......until replacement.If not to bad maybe try Red Line oil which is ester based and in itself is used as a seal sweller in full synthetics.