Synthetic oil

[MiataProtege]

Thinking of going Mobil 5w-30 or 0w-30 if i can find it.... Any one have opinions before I get it changed? Also gonna get an air / oil filter.

Car has 80xxx miles by the way.


Updates:

So I'm still really considering mobil 0w-30... and then for my second switch as it gets warm again to 10w-30, or perhaps just using 5w. though I have a few points... Is the only reason to switch to synthetic because it lasts a longer duration than "dino" (which I'm assuming is regular oil that the manual suggests) and that it might save money in since you only have to replace it at 7500 miles instead of 3000? Or is there a benefit to running high quality oil as I previously thought?

Additionally, I will be changing the oil / air filters and the spark plugs. I found a forum page about using the Mobil #110 instead of the suggested #108 since it was larger and still fit in place. The air filter will be what is suggested. And the spark plugs I'm considering going with autolite platinum's, even though it suggests copper, I have seen a lot of people suggesting these since they are higher performance and still very cheap.

And finally, I will be doing all of this myself, I need the experience in cars, and I've be told lovely stories about how easy the oil is to change in a Miata. If it's as easy as the coolant flush I just recently did, I should have no problem at all.



Thanks for all of your thoughts I am still debating between 0w, 5w, 10w, and to just keep "dino" because my car is used to it. There's a lot of different opinions out there.

[p4R4d0x]

Have you been running synthetic for a while or will you be switching from dino?

0w? In TX?

My car has 10w-30 conventional in it, FWIW. From what I understand, for warmer climates, you want a heavier oil so that when the engine gets to operating temp your oil is still thick enough to lubricate everything. Also, for higher mileage/older engines, tolerances aren't as tight as a brand-new engine, and the thicker oil 'fills out' the space better. I'm no expert, so I'd wait until someone that actually knows about this to comment before making a decision, but I don't think it's something I'd do.

I've also heard it's worse to switch to synthetic on an engine that's always seen conventional than to just stick with conventional. Something about being bad for the seals. Again, I'm not an expert.

[MiataProtege]

I've never used synthetic before, I'll be switching to it. And honestly don't know much about oil.

[p4R4d0x]

I've never used synthetic before, I'll be switching to it. And honestly don't know much about oil.

Then why are you considering switching and thinking about 0w-30?

[MiataProtege]

Then why are you considering switching and thinking about 0w-30?

I've seen people on here use synthetic... and I want to protect my car by any means possible. I figure if Miata people are doing it, I should do it too.

[Nails]

Straight dino here. If I were to use synthetic it would be from when the engine was new. I get my oil tested by Blackstone occasionally and they say my engine is fine and to try 7000 miles between changes.

[Rob®]

Something about being bad for the seals.

False. It will find compromises in seals easier than conventional oil. It can also clean built-up deposits off seals enough that a leak "suddenly" appears. It does not harm seals though.

[p4R4d0x]

False. It will find compromises in seals easier than conventional oil. It can also clean built-up deposits off seals enough that a leak "suddenly" appears. It does not harm seals though.

Good to know. Hence my 'not an expert' disclaimer.

[Rob®]

I'm not by any means either. Just the whole "ruins seals and creates leaks" thing was dispelled long ago.

I run synthetic in my car. But it's turbo. I run dino in the Cobalt and Pathfinder, with no plans to make the switch in either. If I had a not-boosted Miata, I would run dino oil in that as well.

[p4R4d0x]

I'm not by any means either. Just the whole "ruins seals and creates leaks" thing was dispelled long ago.

Someone needs to let the Subaru community know, as they're still hotly debating it

[Rob®]

Every Subaru I've ever touched leaked like a sieve regardless of what oil was used (ambiguous wording ftw). So I don't put much weight into what I hear out of that community.

[goofygrin]

My M5 leaks and burns if using light oils. Use the "must heat in a microwave before putting in the engine" TWS 10w60 and it runs like a champ and burns no oil.

OP: I personally would switch to the synthetic at the factory weight (5w30?), go 7500 miles and then run a BlackStone on it. Monitor the level throughout (every 1k check the oil) and see if your engine likes it.

If you run dino, I'd change it ever 3-4k miles.

[Rob®]

switch to the synthetic at the factory weight (5w30?), go 7500 miles and then run a BlackStone on it. Monitor the level throughout (every 1k check the oil) and see if your engine likes it. If you run dino, I'd change it ever 3-4k miles.

That brings up the cost/benefit ratio. For a street driven NA car that sees 15k a year (currently more than twice what it has been driven up to this point), is the cost of synthetic changes worth the benefit he'll see? Sounds like he is going to pay to get his oil changed. What are synthetic changes nowadays, $80 at least? Figure he'll need two a year at least. Compare that to 4 dino oil changes for the same year/mileage at 3-4k intervals. And like Nails says, he is being told by Blackstone to try 7k mile intervals on his dino oil (my Cobalt regularly goes over 5k on dino oil and it tests good). So you're back to 2 changes a year, maybe 3 for good measure.

I'm not saying not to switch, just playing devil's advocate. I don't remember if OP says he will ever track the car or not, but my guess is that it would be few and far between.

[goofygrin]

Well the first part is the paying someone to change the oil. I think the Miata was one of the easiest cars to change the oil on. No undertrays, filter pretty accessible, etc.

If you can get the cheap Mobil1 synthetic oil from Napa when it's on sale or some other good synthetic (Amsoil) and run it 15k miles then it can work out from a $$ perspective. Not sure how the filters will hold up though.

Personally for me, I use the oil change as a chance to once over the car and check the undercarriage, so every 3-4k (ie. every 3-4 months) isn't a bad thing. My Miata had 150k + miles on it though.

[Rob®]

Personally for me, I use the oil change as a chance to once over the car and check the undercarriage, so every 3-4k (ie. every 3-4 months) isn't a bad thing.

I agree completely. Again, just making sure OP thinks about all sides of the story.

And I use the time when I change my oil to check my car over too, and it only has 98k miles on it. I also run cooper plugs, one reason being that it *forces* me to not be lazy and check out the top side of the engine bay every few thousand miles too, namely making sure the plug tips show that everything is in order.

[Jiggerachi]

FWIW I switched to Mobile1 in the Miata partly because of high mileage and it sees(was supposed to anyway) see autocross / light track duty. Then switched the Element over simply because it's decent oil and i'm a lazy bastard who frequently puts off oil changes. The money I save being lazy more than makes up in extra cost. I change my own oil BTW.

I've recently switched to rotella T5 sythetic blend after reading some of the threads here, it was also slightly cheaper.

[harley]

rotella t5 ftw

[Piff]

Durablend (or whatever it's called now) 10w30. Casual driving. Used it in my 240sx that I owned for 14 yrs as well. Never any oil related issues. I probably won't go straight synthetics until it's the only thing they offer.

Regards.

[MiataProtege]

Updated: Read main post.

[boisking]

I run 6k between changes in all my vehicles on conventional oil. If your engine is in good shape, you can go longer. I think research claims that oil lasts much more than 6k miles before breaking down. The biggest concerns for oil change intervals are debris level and oil level.

MiataProtege, you should stick with 5w30 or 10w30, regardless of what oil you use. For your factory original engine, any type oil in the aforementioned viscosity will be just fine. Synthetic just costs more. No big gain for your application.

There are actually no dead dinosaurs in conventional petroleum oil. Calling it "dino" oil leads to misconceptions about science, which leads to an uneducated society, which leads this thread to the gasbags section.