Oil question: Which oil is best bang for buck? I plan on following the manufacturer's recommended schedule, so I don't want to be changing Royal Purple every 3750 at 5.99/qt. Used Castrol Syntec in my SE-R before and it seemed good, but was only available in 5w50 back then.

Also, I would think 10w30 would be better in SoCal. Any thoughts?

'03.5 Sedan, Silver/Black, Leather, Sport

 

If you're going to change every 3750, there's no real need for the extra expense of synthetic, IMO. I'm thinking about using a synthetic to go to the 7500mi change intervals (the alternate manufacturer's recommended schedule), as I wouldn't want to run regular oil that far.

As for 10W30, I wouldn't go there unless you're in the desert in summertime. The first number is the viscosity when cold, the second number is the viscosity when hot. You want a lower first number, so the oil can flow into the small cracks and crevices quicker when you first start the engine.

I haven't tried it myself (though I might), but many swear by Mobil 1. It's apparently less expensive than other synthetics and works fine for change intervals of 7500mi or less. There seems to be some opinions that Castrol Syntec isn't as good as other synthetics, or that it's not a true synthetic.. the word "hydrocracked" comes up, but I haven't bothered to look into exactly how it's different from "true" synthetics, whatever the definition. Another good source of info on this topic would be the "Synthetic motor oil" topic over on Edmunds.com's townhall.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

 

ryoken thanks for the info about the oil

www.derubeisfineart.com

 

"hyrdrocracked" it was covered on the synthetic oil threads here a while back. Run a search for synthetic oil. In a nutshell, oil in high pressure hydrogen environment with a catalyst to purify the oil.

Note: the coupe manual says to use petroleum-based oils only, where the sedan allows both petroleum based and synthetic.

 

i wonder why the coupe would only allow petroleum based oils only?

'03.5 Sedan, Silver/Black, Leather, Sport

 

Costco sells 5w30 Mobile 1 in case of 6, $24. I think it's good deal

Silver/Graphite/Premium/Sports/Winter

 

I would recommend using a conventional oil if you are going to change oil and filter every 3,750 miles. I use Chevron Supreme 10W-40 in my turbo Passat and it goes 4,000+ miles before having to top-up the oil even though it has almost 70,000 miles on it. It gets an oil and filter change every 5,000 miles. The motor was broken-in per VW's instructions.

I would also stay with Infiniti's recommended 5W-30; and keep any receipts. That way you could stay out of warranty trouble if something went wrong. I'd suggest Chevron Supreme 5W-30. In addition to having a high quality Group 2 base oil it also contains a high percentage of Group 3 base oil which performs, in certain SAE tests, very close to Group 4 (PAO) base oils. I've seen it at Costco for $.85/quart.

So, what will I use in my G35S? The recommended oil for my wife's 325i is BMW full synthetic 5W-30. This is actually a custom version of Castrol Syntec. The biggest difference I can tell is that the BMW oil meets ACEA A3 while the Syntec meets ACEA A1. So, I'll use the BMW oil with oil and filter changes at 7,500 miles, then decide whether to switch to Chevron Supreme or buy another case of BMW.

FWIW, Costco has Mobil 1 at $4.00/quart and a local BMW dealer sells BMW synthetic at $3.80/quart. Not a big difference but I can adhere to the warranty requirements for both cars.

<font color=blue>Dan</font color=blue>

 

yeah, i saw the case of Mobil 1 at Costco for $24, but it didn't seem like that great a deal. but then again, i haven't been paying attention to syn oil prices either.

ok, which would be better for a city street commuter weekday, highway pleasure weekends?

- 3750 dino oil changes, or
- 7500 syn oil changes

i would guess 3750 dino, due to commutes being ~20mins. 3750 syn oil changes are out of the question.

<P ID="edit"><FONT class="small"><EM>Edited by g35doman on 03/12/03 03:10 PM.</EM></FONT></P>

 

I would say as long as your oil filter is capable of handling 7500mi, you're better off with synthetic.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

 

Your driving cycle is close to that of my Passat. I'd suggest 3750 dino oil changes.

I also agree with ryoken on the 7500 syn change if the filter holds up. The differential cost of oil would be $10-$12 offset by saving the cost of one filter. Less waste oil and less hassles.

<font color=blue>Dan</font color=blue><P ID="edit"><FONT class="small"><EM>Edited by dspisak on 03/12/03 04:10 PM.</EM></FONT></P>

 

Just did my first oil hange on my coupe. Could they have made a door on the undertray?

Anyway, I am sticking with my tried and true Pennzoil 5W-30 for three reasons. One, I am going to stick with the 3750 change interval. Two, the Owners Manual states that Infiniti recccomends mineral based oils, third, been running Pennzoil for years with no engine problems in any of my cars.

 

thanks for the opinions, but how can you tell if the filter holds up?

'03.5 AutoSedan, BSilver/Black, Leather, Sport

 

Only sure way to tell is through oil analysis. A cheap filter will clog up and it's bypass valve will open up somewhere before 7500mi -- so you'd be running w/o a filter, and particles would start to build up in the oil. A good filter will hold out longer. Adding a bypass filter to the system works even better, but costs some money.

www.blackstone-labs.com seems to be recommended a lot by the synthetic oil crowd over on Edmund's Townhall. They have plenty of info on what it takes to do extended oil drains. I found them at townhall.edmunds.com in the "Synthetic motor oil" topic in the "Maintenance & Repair" section.

Another interesting read is www.motoroilbible.com.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

 

Another interesting source for info on base oils, etc. is:
http://www.chevron.com/prodserv/BaseOils/

BTW, I am not a ChevronTexaco employee nor am I an employee of a firm that sells ChevronTexaco products.

<font color=blue>Dan</font color=blue>