Hi, my G35S hit 3000+ miles and I am debating whether to put Synthetic oil in it or to wait until _____(please recommend) miles.

On the side note, I'm considering Mobile 1 (5W-30) or Royal Purple (My brother who supped up his MR2 turbo use this). I don't consider Amsol because I just have feeling Amsol is about marketting (searched on google for "synthetic oil comparision" and get nothing but amsol biased articles). What do you guy/gal think?

 

I've heard that you can still notice changes in the VQ engine over the first 8000-10,000 miles. I'll probably change to Mobil 1 on my next oil change as I now have 9,000 on the clock.

A Nissan Engineer said they recommend not going to synthetics until 24,000 km (15,000 miles). There is of course lots of debate about this, so do what you feel comfortable with.

If it were the same price, I'd go with Amsoil, but of course Amsoil's much more expensive than Mobil 1.

<font color=green>GG</font color=green>

 

When I spoke to my service dept they told me that I would still have to have oil changes every 3,000 miles. I thought part of the point to synthetic was not having to get the oil changed as often. What have you heard??

 

I do Mobil 1 5w-30 with stock NISSAN oil filters. I change my oil every 5000 miles and it is still clear. As long as the oil is visually good you can go as long as you want.

I have done that on various vehicles (including a 180k mile Jeep Cherokee) and have had no engine problems


Better Life thru Chemistry

 

In theory, you could strech any oil change to a longer interval, as long as you do an oil analysis which would be prohibitively expensive as a routine. In order to satisfy Infiniti's warranty issues, you should follow their recommendations at least.

However, since they specify different milage recommendations for "Normal" and 'Extreme" (or severe) driving conditions, I think that you should be safe in stretching the oil change intervals to the maximum recommended intervals of the manufacturer when you use a synthetic. Synthetics are expecially stable under severe conditions, ie. many cold start, hot-cold cycles, and stop and go driving.

<font color=green>GG</font color=green>

 

The best decision for you is the one you feel comfortable making. I did my own research and started using Mobil 1 10w30 at 7500 miles, and intend to perform ODI's every 7,500 on both my vehicles...but then, my driving is 85% highway.

The data I based my decisions on came mostly from this site, www.bobistheoilguy.com. Pretty intensive reading but the gys over there are very knowledgable and are very willing to help if you drop a question on the board.


03 G35
02 Sequoia

 

when my G35s had 3166 miles on it i changed the oil to mobile 1 10w30 with the nissan filter. it runs great. now i have almost 4000 miles on the car. i brought in my car to get something fixed the other day and got a loner G with 2500 miles and it felt diffrent then mine!! much faster!! maybe it was the options idk, or i just have one of the slower Gs? idk. back to topic i have had no problems with the mobile one.

 

disconnect your battery for 12 hours and drive it again. You'll be amazed. Someone spotted some HP increase from resetting battery - forget which site but i think it was good for 12hp

 

speaking of oil changes...can the filter be reached from the top? gotta do mine tomm and how much oil does the G take?

 

G's take 5 US quarts, bro, and you have to get underneath to get to the filter.

<font color=green>GSM</font color=green>

 

I've been a synthetic user in all of my engines, cars and boats for years - when I asked the service mgr when to go synthetic on the G he said the rings don't full seat until 20,000 miles so i'll wait till then. I've always used castrol syntec; a pure synthetic at 5W50. I try to change every 3500 but sometimes I'll stretch it to 5000. every syntec motor I've run looked and ran like new at 150000 plus. you really do want to wait to start running the synthetic though - if you aren't broken in yet the rings will never seat right and you'll get blow by due to the viscosity range.

 

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I've always used castrol syntec; a pure synthetic at 5W50.

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Oops...hate to tell you this but Castrol Syntec is not a true synthetic oil. Give me a minute to search, I'll get some data.

03 G35s

 

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I don't think that the term "semi-synthetic" has a standard meaning. Castrol Syntec is made from Group III base oils. That means that it's made from very highly refined petroleum. It does have the legal right to call itself fully synthetic, and it is good oil. Oil base stock fabricated from chemicals is called Group IV (polyaphaolephin...PAO) and Group V (other base oils including esters). These make better motor oil but cost more. The problem most of us have with GR-III oils is that they're priced the same as true synthetics and don't perform as well. If the price is proportional with the quality of the oil, and the consumer understands just what this oil will do and won't do, GR-III synthetics are an OK deal.


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Although an above average oil, Castrol Syntec is not believed to be as good as other true synthetics such as Mobil 1, Royal Purple, Amsoil, etc. Of course I'm not a chemist so I'm only parroting what I read over at www.bobistheoilguy.com. No oil discussion is complete without a visit to bob's site.

03 G35s