From what I've read about synthetics, the primary advantages appear to be that the engine will run up to 50 degrees F cooler under hard driving, engine wear is significantly reduced when compared to dino based oil and syn is more resistant to vaporization/reduction through use. I change oil completely every 7K with filter changes at 3.5K. I use Mobil 1 5w-30. You would probably have to drive your car pretty hard to notice the difference but if you needed to/wanted to then the extra value of sym would be there for you.

'03 G35 Sedan Aero & Sport Package w/Auto
Desert Platinum w/wood dash & cabin trim
Injen CAI, Borla catback exhaust, Tein H-tech lowering springs

 

I changed from dino oil to Mobil 1 5w-30 at 7500 miles, and did a replacement with the same at 12500 miles. I have 16,500 miles on the G35 now, so I will be ready for another change in another 1000 miles. I did not notice an increase in mileage after the first change, but my gas mileage did pick up by almost 2 mpg at about 10,000 miles. I attribute that increase more to the engine finally breaking in rather than the M1.

I have seen quite a few oil analyses with 5000 miles between changes and they were all good, so this is what I am doing with my G35. So far I am using the stock Nissan filter, but I may change from this in the future.

I run the Mobil One in cars that I really like and believe that I will be keeping over the long haul.

 

Thats what I do. I want to have a record of obeying the
warrenty rules of 3750 miles/oil change. My G is worth
the expense of using Mobil1.

2003 Twilight Blue 5AT Sedan, sunroof,
Graphite Leather, splashguards,
12 wire Grounding kit, 350Z duct, Stillen CAI
Underbody rear diffusers, Drilled aluminum pedals
HKS rear section exhaust

 

used Mobil1 at 3k and Havoline synth at 6k 5w30

Cheers, ted


'03.5 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
Click for MODS or Vote at Online Showoff

 

i put in valvoline durablend quasi synthetic, plan to use it every 5k refreashing easy to change the oil on this car!

Mize
Silver 03 6 Speed Sedan/Willow/Premium
Wish List:
18x8 SSR GT1 with 245/40/18 Kumho Ecsta MX
Springs/Shocks/Sway Bars
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