So i recently got my G35 coupe back after my dealership installed a new longblock due to oil leaking past the piston rings and scoring on the heads.

When i bought the G it had 14k on it. Since that day i ran mobil 1 syn. Now i have 32k on it. When i picked up my ride, the service manager told me not to use mobil 1 syn. because the block is aluminum and synthetic oil isnt good to run in our engines. He said they use a synthetic blend in all their cars.

I really want to run mobil 1 because its all ive ever used and has a very good reputation. I seem to think my VQ had flaws from the factory being one of the first 2003 Coupe produced. At least thats what i tell myself...

What do you guys think? Anyone had any engine problems while running mobil 1 synthetic?

Im currently in the break in period (@78 miles now), what oil change intervals should i follow for the new VQ? And when should i switch to synthetic?

 

i've used synthetic oil since day 1 w/o any problems.

 

The VQ (and JDM skyline) had been around a long time before your coupe came out.

I'm around 15K and haven't decided on Mobile1 yet for the VQ...

 

my 2 cents

I've putt 117K funfilled trouble free miles on my '99 max 5spd - have used M1 10/30 since about 12K miles

before that, and please dont laugh, I had a chevy beretta with a 3.1 V6 that I kept till it had about 155K miles - and am sure you guys know how much of a peice of c r a p that thing is. well I drove the heck out of her and she never burned any oil or lost compression. I used M1 15-50. other stuff broke frequently though, water pump, alternator, starter, torque converter - but the engine itself never seemed to fade

friend of mine that had a slightly moded turbo Z - sometimes used M1 and sometimes switched to conventional. He too drove his car aggressively - but never did anything stupid. in the 120K miles or so that he had it - he went thru 3, yes THREE, different long blocks.

anyway - am rambling - but I am planning to switch to M1 when my G's at about 10K or so unless some experts suggest otherwise.

I know it sounds dorky but I like to keep cars a long time and want to challenge myself to make them last - that's why I kept my max - have seen max's with over 200K miles and still running fine.

anyway - also breakin period - follow suggested rules - dont rev above like 4K or so for the first 1200miles.

I also follow this **** rule
have your first oil change at ~500 miles
second at 1K
3rd at 2K
then every 2K
all using a good conventional oil

then somewhere between 10-15K switch to a synthetic - AND NEVER SWITCH BACK TO A CONVENTIONAL.

My suspicion is that your car may have had a few conventional oil changes after you switched to synthetic - I dont know - just a hunch.

also - I dont trust oil change folks at the dealership - I learned that they're the lowest skilled of the techs. I always take M1 with me to the dealer to have them use it in my max. on two occasions they gave the car back to me without using it - and then said oh you can use it next time you come in.

my response - no no no - synthetic only and made them change it again.

anyway - my 2 cents - good luck

 

ive been using M1 since i was at 15k im at 22k now. so with two oil changes and no problems here.

 

Once the engine is broken in, synthetic is best.
Most dealers use synthetic, if yours won't, find another who will.
C.

 

When i picked up my ride, the service manager told me not to use mobil 1 syn. because the block is aluminum and synthetic oil isnt good to run in our engines.

When someone makes a statement like that, it begs for a question to be asked. Why? I can't think of any good reason that synthetic would be good for cast iron blocks but bad for aluminum blocks. If you look at dino and synthetic oils under a microscope, the only differance that you will see is that all of the molecules in synthetic oil are uniform. Hence, synthetic has better lubricating properties.

 

M1 since 3K and now at 27K am fine and the engine is great!

 

Been using M1 since 7500 miles, now at 46000 miles. I've had the oil analyzed at each change and so far they all show a normal to better than normal wearing engine. Here's the proof. Look for the reports for admin.

oil analysis

 

im gonna change mine to Mobil1 this summer.

 

Service Adviser said that???

Here is a response I gave to the synthetic/break in period question. The sprint car engines we build are all aluminum blocks and heads.

Guys, there is no need to wait a certain amount of miles to "break in" prior to using synthetic lubricants. None what so ever. Many manufactures ship their cars out of the factory filled with synthetic oil.

My company breaks in our $40,000 sprint car engines on a dyno with synthetic oil from the first time we start a new engine. We have never had a oil related failure, and have never seen any evidence of improper break in due to use of synthetic oil.

You can take the advise of someone who earns a living building and rebuilding engines, or you can listen to a web based wives tale.

 

Mobile one will not hurt our engines. You can change the oil the second you buy it with 1 mile on the car and will not hurt it. you can switch back and forth between mobile one and regular oil as mutch as you want. You can mix mobile one and regular oil if you want (they even sell it that way as Synthetic blend).
Just because it is an aluminum blcok makes absolutely no difference.
I am a Service advisor for Nissan and we work on the VQ all day. Trust me, the guy who told you that has no clue.
I run synthetic in my cars. I used to have 94 Geo Prizm that I had put 150,000 hard miles on before I sold it, and never put synthetic oil in it.
But I put mobile one in last Sentra Spec V, and it had an aluminum block, never had problems.

 

that's good info - thanks guys - I'll consider switching on my next oil change.

 

Dude your service manager is yankin' your chain and trying to make you feel guilty for your engine getting messed up, I'd just ignore him, he doesn't know what he's talking about.

 

Ive also used M1 5w30 since I've had the car with no issues.