Mobil 1 0-40 for Higher Mileage T5-r?

warmblood58 · Post by **warmblood58** » 03 Mar 2016, 22:58

My new to me '95 T5-r has been serviced with Dino oil in it's past. It has 209,000 and had top end done at 180,000 - should I switch to full synthetic Mobil 1 0-40 for this car? Thanks!

Post by **abscate** » 04 Mar 2016, 02:52

Synthetic for a turbo, yes.

I converted 4 out of 5 cars to synthetic over the last 4 years, with medium to high miles on them, and despite all the doom and gloom of the internet

No hits
no runs
no errors
no drips.

Engine oil usage went down in the cars that used oil via combustion.

Post by **tryingbe** » 04 Mar 2016, 04:56

Any leak? If not, switch.

Post by **oragex** » 04 Mar 2016, 06:22

Survey both the oil filter and the oil level (this last one weekly). If it has seen only non synthetic oil, synthetic oil will cause the filter to clog up quickly. I'd do a filter only change after 300 then 500 miles. Oil level will drop quickly for the first couple of thousands miles.

charleskennedy23 · Post by **charleskennedy23** » 04 Mar 2016, 10:05

When I first got my 98 v70 t5 I put in synthetic oil and it developed some leaks (turbo return line, rear cam seal, and rear main seal). I addressed the first two, added a can of bars RMS stop leak, and started running a high mileage blend. Lucky me the RMS leak went away. I have been running the high mileage blend for about 7,000 miles and my plan is to use the high mileage blend for the next two oil changes before trying full synthetic again. I'm not as experienced as most of the guys on this forum, but this seems like a reasonable course of action to me... Slow transition over to full synthetic instead just switching cold turkey. Maybe you could try something similar if you are concerned about developing leaks.

warmblood58 · Post by **warmblood58** » 04 Mar 2016, 11:28

Encouraging responses, thanks all! I do not have much experience with synthetic other than the Toyota stuff I run in a Prius. I have a Vanagon Syncro that I run Rotella in and an old Alfa gets Castrol

Post by **dyn blin** » 04 Mar 2016, 12:23

The subject of oil is a personal & diverse one, and there are many opinions with experience and support, often contradictory.

Here in NorCal, a 0 weight isn't really needed since our temperatures (never) dip low enough to be needed, but if you're finding a good deal in that weight, or driving to Tahoe for the weekend, it won't hurt anything either. Depending on the previous care for you engine, 40 might be a bit higher than you need, but shouldn't hurt, either (edit- with the exception of a slight MPH hit).

For both turbo and naturally aspirated cars and motorcycles in our possession, I've always transitioned to a full synthetic, and (because I tend towards older cars) also to a high mileage formulation. I note better shearing resistance over time for the motorcycles and turbos, seal conditioners to help slow the wear and tear, the lower volatility of the synthetic formulations reduces smoking for ring-worn engines and the film properties of these formulations I see when tearing an engine down I intuit helps start up protection. I've never seen leaks get worse, and often better with both full synthetic "regular" and high mileage formulations. I've also seen substantially reduced oil consumption.

Although sometimes overkill, I reduce intervals for changes substantially for the first few thousand miles after acquiring an older car, and cut open the filter when changed to see what's being deposited. A submission to an oil analysis company like Blackstone on the first "normal" interval change may help you to get a better idea of the baseline you're starting from, too.

Seaway · Post by **Seaway** » 04 Mar 2016, 12:54

I use Rotella T6 Synthetic and run my car hard a lot. I change the oil about every 6000 miles. It has 197k on it and runs like a top. It burns a little between changes, because I push it hard. Just check the oil when you fill up and add as necessary, In 6000 miles I burn about a quart. The reason I run Rotella T6 is because I can get it in gallon jugs for cheap, it meets or exceeds all the specs for these cars and if Rotella is good enough for my boats $25,000 diesel engine, it is certainly good enough for one of these $400 motors.

warmblood58 · Post by **warmblood58** » 04 Mar 2016, 16:51

So perhaps 10-30 Mobil? Zero seemed a little extreme to me as well. The advice about changing the filter sounds reasonable and makes sense as I would expect stuff to free up with the synthetic -

Klausc · Post by **Klausc** » 04 Mar 2016, 19:13

Synthetic is cleaner and better for the PCV and PTC nipple. 0W40 is a bit extreme for the SF area, I would use 5 or 10W30.

I just bought a real project 95 855T with oil leaks every where, some are still leaking. I immediately changed to 10W30 synthetic and added a RMS conditioner. The RMS stopped leaking and none of the other leaks got worse. The cam shaft rollers look cleaner now, after about 1,000mi.