Learn me: oil numbers and best choice for low-use car?

I know the numbers are a measure of viscosity, and just read that the two numbers together are cold and running-temp viscosity (10W-30 equals 10 when cold, 30 while at normal running temp).

So, just a hypothetical example - a 1987 Toyota MR2 with at least 150k miles (speedometer not working when I bought it 12/2011 and added not even 1k miles myself). Mostly used at rallycross events, occasional weekend drives, very infrequent weeknight cruise-ins when good weather.

What's a good choice for weight? Also any brand name recommends? Otherwise whatever PepBoys has on sale that day is going in. (I've heard of Royal Purple, and believe it's quite expensive. Worth it?)

I run Shell Rotella T oils exclusively in all of my vehicles because they have a high zinc and detergent content, are cheap and readily available at Wal-Mart, and are all-around fantastic oil; choice of dino/semi-syn/syn depends on the car it's going in (dino for the Alfa, semi-syn for SWMBO's Neon R/T, syn for the turbo Saab). In Alfa and Saab circles, Rotella is regarded as the ONLY oil to use. It's good stuff.

Weight choice depends on your climate, there is almost never a "one weight fits all" solution. Check your owner's manual; all engines are different. For example, older water-cooled VWs like THICK 20W-50 or your oil idiot light will go off all the time; put that same oil in a Subaru EJ22 and you'll blow out every goddamn seal in the thing.

That being said a Toyota A-series engine is probably a lot less picky than something like an Alfa or Saab. FWIW I have never heard a single person justify the price of Royal Purple when Rotella is as great and cheap as it is.

If you really want to get crazy with oil research, start hanging out on bobistheoilguy.com - tons of excellent info, but those guys are NUTS

I like a Xw40 weight for beating on, a quality synthetic would be ideal for rallycross and a diesel rated oil for limited use. Shell Rotella T6 5w40 is $20/gallon at walmart.

I use Purolator filters, avoid Fram and anything "E core"(look inside the filter for a plastic cage). Wix and Mann are also good.

Kenny_McCormic wrote: I use Purolator filters, avoid Fram and anything "E core"(look inside the filter for a plastic cage).

+1 on the "never EVER buy Fram." I've seen a few collapse and it ain't pretty. I stick to Bosch when I'm at Wal-Mart and Wix pretty much everywhere else, but Purolator, Mobil, and others also make quality filters.

I've seen oil threads on other forums go insane. Before this one does, here's what I'm going to do with my 160,000 mile Mustang 5.0 sometime soon. I bought a 4 quart jug of Valvoline 15w40 "diesel" oil at the Farm & Fleet store for $12 a few nights ago. I'm going to use thee quarts of that. To that I'm adding 2 quarts of 5w20 Quaker State to get it down to something like 12w37. I figure it'll have a nice all-around additive package when considered all together. Add in that Purolator filter I got at Wal-Mart with the QState tonight and I've got a cheap oil change!

Wait, what was the question?

I'm using Castrol GTX in 10w-30 in the Miata on the track.

Cheap, available and I change it frequently.

I may go to a synthetic this year just to up the intervals and for a bit more heat protection when it warms up.

The guys @ miataturbo like rotella 5w40 and have had the analysis done to back up their findings.

Myself, I use syntec something or other in the miata but will probably switch to rotella. Escort gets fed rotella already. Mx6 get valvoline 20w50 vr-1 or kendall gt-1 20w50.

What does Toyota suggest?

They have tribologists who have done the work to figure out what the oil requirements should be.

Picking wrong can sap power- forcing the engine to use too much effort to move the oil, and even destroy the engine- too thick will not allow oil to move correctly in the engine. Lubrication is more about maintaining the right thickness of fluid between the parts (which is pressure AND flow) than it is to just have static fluid at locations.

Just stick to 10W30 until the engine's so worn that you get oil pressure problems, then move up. If it's worn and you drive it on the track try 10W40. If you drive it in the winter maybe consider 5W30 or 0W30.

Basically for a 4A-series, you want your cold weight to be between 0 and 10 and hot weight to be between 30 and 40. 20W50 or 25W60 should only be used in the very most beat-up old engines that are only running on old-timey Toyota magic, like the 4AF in my 'rolla right now.

BTW the mechanic rebuilding my 4AGE recommended 10W30 for the first 5-6 years of regular racing use before switching to 20W50.

In reply to Swank Force One:

20w50? Why so thick? What pressure numbers are you getting out of this oil in that engine?

pres589 wrote: In reply to Swank Force One: 20w50? Why so thick? What pressure numbers are you getting out of this oil in that engine?

Why so thick? It's in the recommended column of the sticker under the hood.

I'm right in the factory specs for oil pressure... about 42-44psi cruising @ 3k. I used to run Rotella 15w-40, and this gave about a 4psi jump across the range. I'm currently running Delo 400 for winter. Car seems to run much happier than it did when i was running 10w-30 through it. Old turbo cars with motors based on diesel motors like diesel oil with all their fun additives. Especially REALLY LOOSE motors like these.

That being said, i'm sure i could use a new oil pump on this thing... it's probably the original at 200k mile. (Well... 199850 miles on the way in this morning.)

Shell Rotella you say? Need to do some readin' now. 10W-30 sounds like a good start.

Read the fine manual and see what Toyota recommended? What a novel concept, thanks!

I run Castrol GTX in everything.

We bought the wife's '93 Impreza L (It has since been sold.) from a family in Chicago that had owned it since new and put nothing but Castrol in it. At around 130,000 miles it was time for a new clutch and I decided to put some new valve cover gaskets on while the engine was out. All of the visible valvetrain looked brand new and shockingly clean. Especially when compared to the 150,000 mile locked up, sludgy EJ18 from my Brighton that I had mostly run on whatever oil was cheapest at the time. I should have snapped some pics, the difference was shocking.

The L never ticked at all and ran like buttah!

The Brighton (pre-lockup) ticked, knocked and ran like poo.

I recommend Castrol to everyone.

Finally got a weekend free to do the oil change, and Pep Boys only had Rotella in 5W-40 diesel and 15W-40 regular (like two jugs total). Oh well, went with 2nd choice Castrol GTX.

here and there you can get the T6 synthetic 5w-40 for 20 bucks a gallon.

I stock up, and put it in everything(almost).

All Rotella is diesel oil. That is a good thing. You want diesel oil. It has extra additives and detergents for longer wear characteristics, versus Castrol GTX which...doesn't. T6 5W-40 is the good stuff.

Oh no.......an oil thread! That usually results in all out war with the inevitable Fram filters and Mobil 1 will cause all engines to spontaneously explode if they get with in 10 feet of any engine.

Of course that would never happen here.

Feedyurhed wrote: Oh no.......an oil thread! That usually results in all out war with the inevitable Fram filters and Mobil 1 will cause all engines to spontaneously explode if they get with in 10 feet of any engine. Of course that would never happen here.

Ha ha! My '98 Neon's got nothing but Fram filters and Mobil 1. 456,000 miles on the red one and 345,000 on the blue one

I buy whatever is on sale usually. 10W-40 in most of it, and 20W-50 in the Roadmaster. The Roadmaster at 270K gets the thick stuff so it won't rattle as bad on start up and because the clearances in the engine could probably be measured with a yard stick.

I'm pretty much of the philosophy that oil is oil and for general beating, thicker is better. Change it fairly regularly and don't run out. The rest of it is hype and marketing BS. I don't think I have ever heard of anyone having an oil related failure that wasn't contributed to not changing it or not checking it.

Toyman01 wrote: I'm pretty much of the philosophy that oil is oil and for general beating, thicker is better. Change it fairly regularly and don't run out. The rest of it is hype and marketing BS. I don't think I have ever heard of anyone having an oil related failure that wasn't contributed to not changing it or not checking it.

The problem is that is only true to a point. If you put parts store brand conventional in a T7 Saab you will blow the motor up so quickly from sludge it is not even funny. Even semi-synthetic isn't good enough; a board member here killed a motor in his 9-5 because he didn't read the TSBs. Same with Alfas. They need oil with a high ZDDP content and the valves will tick and clatter like crazy if you don't heed that warning.

In a lot of engines it makes no difference, but some are VERY picky.

SlickDizzy wrote: All Rotella is diesel oil. That is a good thing. You want diesel oil. It has extra additives and detergents for longer wear characteristics, versus Castrol GTX which...doesn't. T6 5W-40 is the good stuff.

Duly noted for my next visit, thanks!

I run Rotella in EVERYTHING, Mitsus ,Subaru and all bikes. Good E36 M3

Swank Force One wrote: The guys @ miataturbo like rotella 5w40 and have had the analysis done to back up their findings. Myself, I use syntec something or other in the miata but will probably switch to rotella. Escort gets fed rotella already. Mx6 get valvoline 20w50 vr-1 or kendall gt-1 20w50.

Is the Rotella synthetic? Any idea on what kind of intervals they are getting with track use? Although I'm N/A so I won't be hurting the oil nearly as bad.

I may do that on the next change.

z31maniac wrote: Is the Rotella synthetic? Any idea on what kind of intervals they are getting with track use? Although I'm N/A so I won't be hurting the oil nearly as bad. I may do that on the next change.

Rotella comes in three flavors: T (conventional), T5 (semi-synthetic), and T6 (full synthetic). I think T6 only comes in 5W-40 so that is probably what they are using.

parker wrote:

Feedyurhed wrote: Oh no.......an oil thread! That usually results in all out war with the inevitable Fram filters and Mobil 1 will cause all engines to spontaneously explode if they get with in 10 feet of any engine. Of course that would never happen here.

Ha ha! My '98 Neon's got nothing but Fram filters and Mobil 1. 456,000 miles on the red one and 345,000 on the blue one

Me too. I have used them for years, even with rotaries! That's the joke! But those two things, in all the oil threads anyways always end up coming from Satan himself to destroy anything mechanical.