Gents,

From the last thread I can see that there is much misconceptions about viscosity and oil types. A couple of points to keep in mind when buying oil for your next 6.5 oil change:

- 15w 40, the first number designates the cold weather startup performance of the oil. The second designates the oil viscosity at engine operating temp. Neither of these numbers are actual measures of viscosity. These numbers are more like a trade designation, 15w 40 actually has a viscosity of 15 centistokes at engine operating temp.

-no matter what you have to have a 40 oil, thats what your engine is built to use.

-the first number will tell you how well the can lubricate the engine during cold starts, the lower the better. 0w and 5w are excellent winter oils.

-API Label: CJ-4, CL-4...these values indicate the oils emission system compatibility. First Letter: C (diesel) S(Gas). Second Letter: year of vehicle compatibility H (1998) L (2002) J (2007) and so on. Number: 4 stroke or 2 stroke.

Buy a 0w 40, 5w 40 or 15w 40 based on temperature outside and have a CJ-4 API label and you will be just fine, meeting and exceeding OEM specs. Using 0w 40 in the summer is ok, however its a waste of money because it give you no advantage.

Also synthetics do NOT allow for extended oil change intervals unless you doing oil analysis. Oil change intervals are set because oil becomes contaminated over time not because the oil wears out. Leaving dirty oil in your truck past the recommended interval is not saving you money. Regular mineral oils will work every bit as good as an expensive synthetic oil, the advantage of synthetics is there cold weather performance. Unless your engine calls for a synthetic using one is a waste in the summer.

Synthetics can increase fuel economey, be it very slightly, it will never pay for the increased cost of buying the oil.

Hope I have set the record straight.

Synthetics can increase fuel economey, be it very slightly, it will never pay for the increased cost of buying the oil.

I tend to agree, but there a whole lot of people out there that actually believe synthetic is giving them a lot better mileage and lot more horsepower.
Apparently Dino oil is so low in lubricity it creates drag and slows your motor down, robbing horsepower. Dino oil is so bad for an engine you'd be better off using five quarts of sand in it.

The things some people will believe.

As to the numeric designations, I still run into people who don't understand that. Old timer mechanic I know tried to tell me that W means winter, and you should only use 15w40 because it is the all around best for any engine. Did I mention he is a small engine mechanic? He put 15w40 in all the new small engines with no break-in, plus ran it year round in all the shop trucks (gas). Because it's good for the big John Deere and Cat equipment engine, it must be good for a 5 horse Honda too.
Seemed like we bought a lot of replacement engines from Honda every year or two. Just blamed it on wear and tear, or lack of maintenance.

five quarts of sand....lol

I tend to agree, but there a whole lot of people out there that actually believe synthetic is giving them a lot better mileage and lot more horsepower.
Apparently Dino oil is so low in lubricity it creates drag and slows your motor down, robbing horsepower. Dino oil is so bad for an engine you'd be better off using five quarts of sand in it.

The things some people will believe.


There is tons of dyno proof that synthetic oils increase HP but as stated, unless you run an external filter setup, its pointless due to the soot.

I will not run dino oil in my turbo Caravan, due to the boost I run and the abuse I give it. I also run synthetics in my Jimmy and my dads Trailblazer and run them to 10,000 km's before I change it.

20,000 miles between changes using Mobil 1 Turbo Diesel 5w-40. Before you have a stroke, read my sig..