McFly09

I know this is very subjective but I thought I'd look for some expert advice before I make a purchase. A little background....

I plan to change the oil once a year, I drive under 1000 miles a year
Stock ZO6, under 15k miles. Pleasure driving only.
My car does sit without starting sometimes for up to a month.

I was considering Hemmings Classic Car oil
http://www.hemmings.com/classicoil/

I have read a little about the Amsoil Z-Rod.

Whatever would protect the engine from cold starts, corrosion, and general wear. I live San Antonio, TX and generally I won't be driving the car when it's below 40 degrees.

What recommended weight and oil should I be looking at?

aaronc7

Mobil 1 5w30 extended performance?

PLRX

Read the owners manual.

MY03C5Z

Im sure you would be fine to stick with the factory recommended oil. Thats what Ive always used. Will be switching to M1 10/30 though. Most recommend it for performance driving if the car is run in weather above freezing.

TheDVS1

I've been running Royal Purple 5-30w for years and it holds up well with my "extended" change intervals. I like that I can find it at Pep Boys, and with my frequent discount coupons I don't choke too badly on the price.

McFly09

From what I gather 10w-30 is the way to go unless you live in a cold climate.

The local Advance Auto parts carries Royal Purple, I'll look into it. I think they are similar to Amsoil.

Does anybody else use the Amsoil Z-Rod oil? I was leaning in that direction.

rbartick

Factory recommended Mobil 1 is just fine. My stock car sits just as long as yours. My bikes sit longer.

PeteZ06

Been using Royal Purple for years on car and bike. Its the only oil I've used that keeps its almost original color after a season of use.

04zjimc

I use 0-30 Castro European Formula for summer and winter.

Randy Richards

A lot of of different opinions... But I have used Mobil 1 since 1982. I've used it in i every thing from Vets to tractors. And everything in between.if you want something you will probably never have to worry about USE MOBIL 1. PERIOD end of story!!!!!!

bikeriderga

No need for you to run a high dollar synthentic with no more miles than you put on the car.

The recommended Mobile 1 would serve you fine, since you are going to change it once a year anyway with less than 2K miles on it.

I personally run Amsoil, but I put about 5K a year on mine.

spdislife

Amsoil ZRod

Regarding what the owner's manual recommends, keep in mind that's 10 year old information and oil formulations have changed.

WannaC5Z

OEM Mobile1 5W30 Full Synthetic or I used Valvoline 5W30 Full Synthetic in my road raced Mustang Cobra for many years never with an issue.

C66 Racing

AMSOIL Z-ROD 10w30 Synthetic Motor Oil (Product Code ZRTQT)
(zinc – 1440 ppm, phosphorus 1320 ppm)

I think this would be a good choice for your use, but recognize it doesn't meet what was the OE spec (GM4718M) or the current GM spec (dexos1) as it has too much phosphorus, an anti-wear additive limited to 800 ppm by the API due to concerns over cat longevity. Given your limited mileage, I wouldn't worry about that.

The Z-ROD is very similar to AMSOIL's Dominator Racing 10w30 that I use in my 02 Z06 at the track. The Z-ROD has sufficient detergent/dispersant for 3-5k mile (or one year) oil change intervals and has very strong levels of zinc and phosphorous anti-wear additives. Additionally, as it is designed for flat tappet classic cars which are stored often, it has rust inhibitors which would likely be of benefit to your limited use.

With it being a 10w30, you'd need to be very careful on warmup. My own personal thumbrule is ~half throttle and ~half rpm until the oil is at least 150F.

More than happy to get AMSOIL products for forum members at dealer wholesale pricing, about 25% below retail, via the AMSOIL Preferred Customer Program. Drop me a PM if interested.

Brock63

ZRod is a good choice but for only 1000 miles per year the MORE IMPORTANT aspect is changing oil every year as your block will leach out contanimants as it sits...plus the collection of water moisture will occur so be sure to FULLY WARM the car for an extended period of time to burn off any moisture completely. A quick start up and run up for few minutes does more damage than letting it sit until you can run her properly.


Good luck....

McFly09

C66 Racing - Thanks for the info on Z-Rod

What risk is there to the cats? Is it actual risk or something along the lines of "this product has been know to cause cancer in the state of california" ?

Brack63 - Thanks for the advice on warm up.

I'm usually real easy on the RPMs until the oil temp is close to 180. I'm pretty easy on the car regardless but I certainly don't step on it until the oil is very warm.

C66 Racing

I think it is more like the latter. The current API SN spec limit on phosphorus is 800 ppm. Good oils in the early to mid-2000s typically had about 1200 ppm and the Z-ROD has a little more than that at 1320 ppm. To meet EPA regs, the emission system has to meet spec for 100k+ miles. Simplistically, if an 800 ppm oil will ensure the cat works up to 100k miles, a 1320 ppm oil with otherwise similar properties (e.g. volatility) should last to 60k miles. At 1000 miles per year you will likely never get there.

This is overly simplistic. The cats won't fail instantly at 100k, rather degrade over the life of the cat as the phosphorus inhibits the catalytic exchange process. The cats don't clog from phosphorus and unless TX has emissions testing, you'd never know if they were degrading or not. The 800 ppm spec was set so that the average conventional oil wouldn't prevent the cats from meeting spec at 100k+ miles.

But oils do not have the same volatility (e.g. how fast they evaporate carrying phosphorus into the exhaust system either via piston ring leak by or via the PCV system). AMSOIL's synthetic basestock has very low volatility compared to most conventional oils that the API standards are set for. Though dated now, a 2009 volatility test done by AMSOIL showed their Signature Series 5w30 had a volatility of 5.7% per ASTM D-5800 and as a comparison Chevron Supreme had over 14%. This would indicate that even with the elevated levels of phosphorus, the Z-ROD would do less damage to the cats than a typical mineral oil complying with the 800 ppm limit would.

TXGS507

M1 10-30 for me...

LT1driver

03Z, M1 05-30 since new, 73k now and no issues....knock knock

JrRifleCoach

OH boy!
An oil thread.....

Mobil1 and Fram filters