Prairiedawg

M1 5w50. Thanks for pointing that out, I'll edit the post.

Charles Navarro

Typically ethanol free fuels are formulated with the same levels of additives as top tier fuels. If I had a choice, I'd run ethanol free fuels with the lower octane over a top tier E10 at 93 octane.

Whenever switching brands of oils, I'd expect the first UOA to be a little wonky. It should resolve itself by the second UOA.

silver_tt

Yes and ethanol has a higher octane number than gasoline -- so it is effectively an octane booster when added. Eg. mixing a gallon of 91 octane pump gas with a gallon of E85 you get something like two gallons of a ~96-octane fuel.

So naturally I would run the 91 ethanol free as well. You are very lucky because where I live there is no ethanol free gas and the only places that have them outside of the city are not Top Tier (e.g. "Joe's gas stop") so I don't trust their detergents even if it's ethanol-free. If I had access to Shell or Top Tier ethanol-free it would be a different story....

Petza914

This advice would only apply to normally aspirated engines. If supercharged or turbo charged you should go the other way and run the higher octane fuel with up to 10% ethanol.

Also, if you've been running ethanol blended fuel and switch to non-ethanol, you can force phase separation of what was in your tank and force the water out of the gas. The water is heavier and will end up at the bottom and be sucked into the fuel pump and you'll wonder what just happened to your engine. If you have any water in your tank, filling up with the ethanol blend will absorb it, but filling up with non-ethanol doesn't.

Charles Navarro

The phase separation can indeed be a problem. I wouldn't go around switching between ethanol free and E10 repeatedly as you're going to indeed run the risk of this happening. If you aren't sure you can always get ethanol free, I'd just stick with E10 plus a fuel additive like Driven injector defender.

I don't have access to ethanol free and I put Driven Defender in all my cars every other fill up.

Charles Navarro

I'll throw out there that even through the 997 models Porsche does not approve the use of even E15. For models prior to the Boxster or 996, Porsche doesn't recommend more than 5% ethanol, which means E10 isn't recommended.

Petza914

This is exactly what I do with 93 octane E10 as well. I bought a bunch of 2 oz glass bottles with sealing caps and prefill them with the carb defender concentrate. I keep about 5 bottles in each car. At the gas station I dump in one bottle, fill up the car and off I go. Since I never know how long one of the cars may take to go through a full tank of gas, I add it to every tank.

Prairiedawg

Thanks for the advice guys.

Yeah, I'm lucky to get the ethanol free here. I have to drive to the next county over to get it it but that's where I typically drive anyways. SE Wisconsin counties along the lakeshore require E10 but central and western Wisconsin do not. I'll usually leave at least enough gas in the tank to get out that way for a fill up and top off before I come home. Occasionally I put in 93 but i try to avoid it if I can. Western Wisconsin has some fun roads to drive and E-0 to boot. I just make sure to use name brand fuel and always fill with it before it goes into winter storage......like next week......sniff.

Thanks for validating my instincts.

Cheers.

silver_tt

That is right. I was using E85 as an example to show octane boost but in general for all older engines it's not recommended because of corrosion to fuel system components that were not designed for it. And to run E85 you specifically need a flex fuel engine (my Audi is flex fuel, I don't run E85 and never have but I saw the engine has an ethanol sensor and the ECU remaps timing if it detects that you are running E85).

I would just say that pure-gas.org is an excellent resource but it is crowd sourcing data and user maintained. Like many things in life, it is not perfect. My father and I have found that gas stations will change gas or owners sometimes, etc (he will actually go up to the gas tanker driver and talk to them about the gas if he sees them)...and may no longer be ethanol-free. Excellent website and resource but always double check.

cjarrett

Got my first oil analysis done. Seems to all be in pretty good order, good considering 100,000kms I imagine. I use Motul synthetic and Liqui-Moly MOS2 every 6 months.

Petza914

That is A LOT of Copper (maybe main bearing wear or valve guide wear) for only 2,200 miles on the oil. I see single digits with 5,000 mile oil runs.

cjarrett

"Copper tested a little outside the average range in this sample from your 911's engine. The averages are based on typical wear levels for the Porsche 3.8L H-6 engine, after 5,500 km of use. Your oil run was shorter, yet copper is already higher than average -- it shows accelerated brass/bronze wear, unless maybe it's wear-in from any work you've done to the engine within the past couple of oil changes. The other metals look great, and there's no contamination here. This isn't enough copper to go searching for an issue, so let's just see how it trends."

I had installed a new IMS and chain tensioners fairly recently but I don't think those have any copper/brass/bronze in them?

frybear

My cooper was at 19, average was 9 according to Blackstone and after using Driven DT40 and driving it for 2000 miles, went down to 4

Petza914

That recent work shouldn't impact copper IMO.

For comparison, here's an 05 C2S history with 108k miles on it using Driven DT40. Even when I missed my change interval and ran 7,800.miles, the copper was still learning than 1/3 of yours.

cjarrett

Will monitor with the next changes, maybe try switching to the Driven oil as well.