Is synthetic necessary?
 

I know this has been beat to death, but I can't find it. All the oil threads are about which BRAND and what WEIGHT.

Is synthetic oil necessary for a water-cooled turbo that sees only street and autocross? I change my oil and filter every 5000 miles, and I would use some kind of high quality dino oil (Castrol GTX or Rotella). I just cringe every time I go to Pep Boys and see they want almost $40 for a jug of Mobil 1. Yes, it's cheaper at Wal Mart, I am just already cringing when I am there, so the effect in my story isn't as good.

I have always run Mobil 1 in my turbo cars and not thought much of it, until I bought my Outback XT and read on the forums that they recommend Castrol GTX because of the short oil change interval (3750 miles). It made me wonder if the cheaper dino oil would be just fine for the miata as well. It would also cut down on the number of oil jugs I have to keep around.

So, Any thoughts on this played-out topic, or links to the playing-out?

By the time 3750 miles comes around in my outback, I have already added another quart or two. I change the remaining oil and filter at 6k. I am all highway miles.

I run synthetic only cause it's better and cheaper/easier than going back into the engine for whatever reason.

"Synthetic oil" doesn't mean what it did a few years ago. There are cheap, "non-synthetic" HDEOs that outperform "synthetics" at half the price. A couple hours reading oil analysis data will tell you which oil to buy.

Google it. Tons and tons of info.
But the short version is, imo: synth>conventional because you can run it longer, and it will tolerate heat/abuse much better.

Something awesome like Rotella t6 full synth not only has all the properties of full synth oil, but is superior to many full synth oils, and costs only a couple bucks more than conventional. win win win

Go read on BITOG, look at oil analysis reports if that suits you, and get a feel for which dino oils they recommend (if any) for turbo cars. If you're paying $40 per oil change you need to shop around more. Advance/AutoBone run deals for 5 qts of Mobil 1 plus a filter for $30. Last I checked the oil geeks still liked M1 0W40 and it's what I run in my n/a Miata. Oil geeks also like Rotella T6 synth (5W40) and that's about $28/jug every day at Advance and often goes on sale for less, and that's what I'll run when the turbo goes on. If you have another car that likes 5W30 I believe that Pennzoil Platinum usually tests well in UOAs and is less than $25/jug at Wally World. If you're buying jugs that don't come in a deal with a free filter, Purolator PureOnes can be had at decent prices from Amazon, sometimes on sale for $3-4 per with free shipping.

So what kind of OCI do people run with like T6? If I could go 10k miles with that, or even with M1, that would more than offset the cost of changing dino oil every 5k miles.

I don't pay $40 for M1, that's just what Pep Boys wanted. I usually venture to WalMart where it's like $25 or something. It's still kind of expensive though.

I run the 3700mi OCI on the outback because I'm afraid of that turbo failure they talk about. I checked the banjo bolt and mine was fine, so I plan to keep it that way. How much oil use is normal for those engines?

that's because mobil1 isn't full synthetic anymore.

Show me a group IV synthetic that's less than $10/qt.

I do 10k changes on my GF's Cherokee with 5k filter changes on blue bottle Rotella. I will try blue bottle Rotella in ky daily and report back on the right change interval. I do 4 track days on blue bottle in the track car and might switch all cars to white bottle soon after some analysis data.

I'd like to try the 10w30 white or silver bottles and see what they do.

I usually pay $22 for blue bottle and $14 for white bottle, both in one gallon sizes. this oil makes sense in every way.

dude, i just buy whatever's the cheapest with a filter at advance auto. i dont care.

been getting alpine brand a lot lately. like $15 for 5qt with a purlator filter.

but you have a stock 1.6 motor that you don't care about. you'd probably be a lil picky with a built vvt motor. maybe not lol

i have a stock 1.6L that i care much about.

but i drive it maybe a total of 5K a year.



I dont care about my altima, in which i tend to just replace the oil when the light comes on.

You check the filter at the BLOCK. There is no filter at the turbo

I just read all the Oil 101-109 articles on BITOG. After reading all that, it would seem like an easy choice to use synthetic 0w-30 and go for a 10k mile OCI. That will be cheaper than 5000 on dino oil, and I could change the filter at 5000 miles if I get nervous. I do think I will stick with 5w-30 dino oil in the Subaru, since I think it's particulates that force the 3750mi OCI on those cars.

If that were the case you could change the filter rather than the oil on the subaru.

Anyone ever use or know anyone that uses Eneos 0w50? I think that's what I'll be running in my mine. I debated on the amsoil 15w-50 but the Eneos looks to be a better oil to me on the stats having the higher 192 viscosity index. I'll be using the Amsoil break in oil for the first 1000 miles or so.

I gotta give MINI credit. The Countryman self-analyzes the oil (or driving habits, or both) and tells you when it wants new oil. People report 10-12k oil chance intervals pretty regularly.

Caution non-turbo answer below. But long-term answer.

I think "necessary" would be damn hard to define comparing synthetic vs blend vs more frequent changes of a quality conventional oil.

Changing a conventional oil more often might not even yeild benefits compared to running a full synthetic, because a conventional still has a certain amount of long and short chain structures. The long chain ones vaporize, the short chain form sludge as they drop out of solution. It might be that even with frequent oil changes a conventional will still generate deposits fractionally.

I've run Mobil 1 since 10K miles (about 19 years ago) and the last time I had my valve cover off (2 years ago... not a huge wrencher like most on here) everything within was bright shiny metal, no deposits or brown stains. I don't drive the car enough to object to the cost or do some of the good sleuthing like some have done on here. I find the full synthetics to be a superior product so I just run them.

Full disclosure, I run whatever the manufacturer says in my DD's. They will be passed to another owner 8-10 years from new, so I don't care about them that much.

As far as oil for the turbo's sake, you really want something that is resistant to coking in the bearing. That's why water cooling was developed. Other than that, it's your call for lubricity and viscosity.

Really now?

Do people that race/abuse/treat their minis right

report that the oilchangeme interval drops?

Our 2006 Odyssey has this feature as well.

Since when is Mobil1 Synthetic not full synthetic?

Edit: ok, some google yielded some threads on BITOG. Meh, it's synthetic enough. Cheetahdriver likes M1 (among others, of course) and that's good enough for me.