I was thinking that perhaps Nissan was worried that people who used synthetic oils would not change the oil or filter as often. Therefore, even though the oil would not break down, it might collect particles that would damage the engine over time. I can't think of any other reason that synthetic would be cause problems (other than what CoZ mentioned about it typically being a ligher weight).

Anyhow, I've been using Mobil 1 since my first oil change. I changed at the following intervals

3000
6000
10000
15000
+5000....

I'm now at 18,500 without any problems. Hopefully things stay that way...

-D'oh!

 

I just switched over to synthetics today. I'm currently at 9000 miles and i'm running Royal Purple.

 

I use Mobil 1
changed at:
3698
6263 before track day
6702 after track day
8192 after track day.

 

My oil change schedule was as follows:
500 miles - Valvoline Semi-synthetic (mid-Nov)
1000 miles - Mobil 1 (Dec 03)
2500 miles - Mobil 1 (Feb 03)
5000 miles - Mobil 1 (May 03)
I'm at 6900 miles and will change it within the next week or two. My above mileage is approximatly when I changed it.

 

The only issues I have seen is when you use synthetic before 8- 10k kms. Past that I cant say that I have had an issue.

We always use Motul oil and never had an issue. This is in some very high powered VG30s, RB25, RB26 and SR20s Nissan motors. One friend that has a 400+rwkw R33 GTR has been using Motul for sometime and after drags, track work, motokhanas, for 20,000 kms or more has no issues with leaky seals, turbos or anything.

Mike

 

It's possible he could have been confused. From what I've been reading around here synthetic tranny and diff fluid is not recommended and may cause damage.

But that is not motor oil, and I don't think any engine is "designed for" synthetic oil. It's just oil; a better oil, but just oil. Nobody designs an engine specifically for synthetics, if I'm not mistaken.

 

Has anyone used Amsoil synthetic oil in their Z? I have heard it was better than Mobile 1 and was thinking about using it. I was also thinking about using Amsoil transmission fluid too. Any thoughts or suggestions.

 

Best to run the first 10,000 miles with mineral oil based, then go to a synthetic.

But, DO NOT switch from mineral to synthetic after 60,000 miles!

Mineral based oils leave carbon deposits on parts and the oil seals get worn to the new size(from the carbon) and the synthetic oil (being a high detergent oil) will remove the carbon deposits from these parts and engine starts leaking oil from every shaft seal.

BTW,..... BMW, and Mercedes say, DO NOTswitch to synthetic after 60K.

Scott

 

ZPirate- I am using AMSOil 5W-30 in the crankcase and Series2000 Gear Lube in the MT and rear diff.
Excellent choices- the gear lube made a great difference in the MT.
Very happy with the AMSOil and it is several notches above the Castrol Syntec I was using in previous vehicles.

 

I had found this TSB awhile back concerning tranny oil. It looks like Nissan won't back dealer warranty work if their tranny oil is not used. Not sure how this all works out, but just thought I'd pass this along.

http://www.nissan-techinfo.com/nissa...3.asp?mscssid=

 

Z'd, What was your mileage when you switched to Amsoil? Currently I have only 1,500 miles on my car, although I have had it since January 16, 2003. I usually only drive it on weekends. I had my first oil change at 1,200 miles using oil supplied by my dealer. I would like to change it again at about 2,500 miles and start using Amsoil then. I have heard great things about Amsoil, including using it in the MT and rear differential. Thanks.

 

I changed to a Castrol synthetic blend at 1400 miles and AMSOil full synthetic at 2800. I just changed the rear diff and MT at 4100. Am up to around 4600 now. Same situation as you- got the car last December but couldn't drive it much this winter!!!!

 

I switched to Mobil-1 at ~3500 miles. I'm running standard fluids everywhere else.

Speaking of which... pushing the car hard (as hard as you can in daily traffic and the occasional autox that is), how often would you guys change things like tranny and diff oil?

 

i brought mobil 1 to infiniti for my oil change and they didnt question it.

 

Why would you drive 10,000 miles on regular oil then switch? why not use it from the start

MYTH: You should break in your engine with conventional oil, then switch to Mobil 1.
FACT: You can start using Mobil 1 with SuperSyn™ in new vehicles at any time, even in brand-new vehicles. In fact, Mobil 1 with SuperSyn™ is original equipment (it is installed at the factory) in:


Chevrolet Corvette
All Porsche vehicles
Mercedes-Benz AMG vehicles
Dodge Viper
Ford Mustang Cobra R
All Aston Martin cars

One of the myths that persists about Mobil 1 is that new engines require a break-in period with conventional oil. Current engine manufacturing technology does not require this break-in period. As indicated by the decisions of the engineers who design these high-performance cars, Mobil 1 with SuperSyn™ can be used in an engine from the day you drive the car off the showroom floor.

i got this from www.mobil1.com

 

Hmm... yeah I'd have to say that's probably true if Corvettes, AMG MB's, Porsches, etc. come with it in the crankcase when you drive it home.

 

I have read that AMSOIL beats Mobil1 in ALMOST every test out there EXCEPT for ASH content. Ash content is HIGHER in AMSOIL than in Mobil1.

 

jckolnturn wrote
Because synthetic is "too good" at preventing wear. The wear nessesary to wear-in the rings for a tight gas seal.

You can read all the propaganda on new cars coming with mobile 1, but engines will not make there full power potential if you run this very good oil too early in their life.

I have taken apart a corvette engine, (mobile1 from new) and the factory "cross hatch" honing marks where still visable at 50,000 miles! Can you say blow-by!

Lycoming aircraft engines says "NO SYNTHETIC FOR THE FIRST 50 HOURS OF OPERATION"

Synthetic is great oil, BUT IT IS NOT WHAT A NEW ENGINE NEEDS FOR PROPER BREAK-IN.

Once you put synthetic in, you effectivly stop any chance to finish the proper break-in on the engine.

I want my engine to "stay" at the 10,000 mile mark for it's entire life. 10,000 miles is when a typical (not abused) street car engine is it's fastest.

Your car, do as you like!

Scott

 

Listen to this guy! He's is very knowledgeable. My engine is at 10,800 miles and has never been better.
no revs above 4K until 1600 mi and no syn oil change until 5000 mi.
my **** retentiveness has finally paid off for once in my life!

 

This subject was covered months ago and rejected as complete B.S. I don't know why your Service Manager thinks anyone will let him get away with perpetuating this myth, but it pisses me off every time some bozo reinterprets the company policy. In your owner's manual it says Nissan recommends mineral-based oil, it does NOT require it! On page 9-5 of the manual, it says only those oils w/an American Petroleum Institute(API) certification should be used. The symbols and language say, "API Service SJ, SAE 5W-30, Energy Conserving". Any oil that falls into these categories should be used, according to the language on that page. If Mobile 1, Castrol, etc. fit the category, they are acceptable.

It is only after the requirements are so stated, that it says, Nissan recommends mineral-based oils. If you or anyone else is concerned about bringing your own oil, have the Service Writer write on the ticket, customer brought own oil and the brand and API Certification, I will do so when I change to Mobile1.

As for your Service Manager, ask him for written statement(s) from Nissan "techs" that supercede the language in the owner's manual. I think his dealership stocks the oil he wants you to use and pay for, not any tech advisor.

Do a search in the archives on this subject, you will find an "OFFICIAL" Nissan Engineering Manager for NNA's Policy Statement which verifies what I just said. I don't know how much you want to deal with this SM, but I would look for another dealer to do my warranty/maintenance if you shove the NNA Policy up his nose.

BTW, if any leakage from seals result from changing your oil brand and composition, change back to the original oil. Any damage is very unlikely to occur, it just goes back to status quo.

Boomer--my advice, use it or lose it, I don't care.