Oils,Grades/Spec's 4th Gen

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Oils,Grades/Spec's 4th Gen

Post by cowboy1sf » Sun May 05, 2019 10:33 am

Found this interesting chat, however always do your own research & check your gen's requirements. The info below is referring to 4th Gens. :thumb:

OEM small block spec is a 30 grade. Simple as that. Running power adders, racing, etc... isn't going to change this spec as that spec already has that taken into account.
These engines are tested with the Sequence IVA 100 hour endurance test which is a sustained high rpm, high wear test for 100 hours with intermittent load. Even 20 grades pass this test with flying colors. If you drive it like grandma and never go over 2500 rpm and 20% throttle, a 0w-10 oil would work just fine. The 30 grade already accounts for the highest stress scenario. Running a higher viscosity/grade than that just increases bearing temperature, increases aeration, and robs power with nothing gained.
Also, the "w" in 5w-30 doesn't stand for weight. It stands for winter, since the first number indicates cold start pumpability.
20w-xx = -6*F
15w-xx = -14*F
10w-xx = -23*F
5w-xx = -31*F
0w-xx = -40*F
Adjust the first number depending on your climate. There's no reason to increase the second number in the summer, say from a 30 grade to 40 grade, since oil temperature is much closer tied to coolant temperature than ambient temperature. All the higher viscosity oil will do is increase aeration which in turn will increase oil temperatures, especially in the bearings,However some people that have used a 40 grade oil have said that their engine runs a tad quieter?

Three of the most popular Oils used are Pennzoil mineral,Mobil 1,& GM fully synthetic. all 5w-30
Mobil 1 can cost anywhere between £50-75 quid for 5lts however I have managed to pick some up on ebay for £45 per 5lts at times. Ebay/Autopontiac/American Auto parts.
Pennzoil Mineral i can only seem to find it sold by the 1lt Bottle between £8-£12 quid per 1lt.
GM Oil Fully synthetic can also be found on ebay at around £20-£30 quid per 5lt- Ebay

Pennzoil Mineral: sold at - Ebay/Autopontiac/American Autoparts Redhill
Mobil 1 Fully synthetic - Sold at- Ebay/Autopontiac/American Autoparts Redhill
GM Fully synthetic - Sold on Ebay

What are you using? Hopefully NOT Tesco's oil :panic: :shock:


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Re: Oils,Grades/Spec's 4th Gen

Post by bhm1712 » Sun Oct 13, 2019 12:32 pm

I use Mobil 1 full synthetic.
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