Hi,

Is there any general consensus on what the best high mileage formulated 5w-30 is?

what type of engine and what climate and driving style?

In addition to what lewkoil said I would like to add another component, the gradient:

1. Flat roads = x mileage
2. Uphill roads = x-y mileage
3. Downhill roads= x+z mileage

Hussam Adeni

Guys,

I'm just wanting to know what the best "high-mileage" 5w-30 oil...application makes no difference.

Best high mileage oil? Well there is only one synthetic (perhaps Group III type synthetic) high mileage oil that I know of and I would rate it the best: Valvoline Maxlife Synthetic. Good zddp levels; a boatload of calcium for detergent, anti-acid, and anti-wear; and a nice slug of moly (around 300 ppm). O'Reileys (if you have them) is running a special on Maxlife Synthetic for well under $4 a quart.

Now if you want to go with conventional oil in high mileage, I really like regular Maxlife, which has about 12-22 percent PAO in it, but if you want really high zddp get Citgo Ultralife.

Thank you TallPaul.

What's the best conventional high-mileage oil? Maxlife, Citgo, or something else? How do the Pennzoil and Castrol products compare?

I assume you are in US or Canada. I would look for the brand high mileage oil that does not have SM designation, nor starburst or "energy conserving" as all these designations are fuel economy driven to the extreme. That is why I believe the high mileage oils are closer to what the basic motor oil should be.

You will want to look at product data sheets too. If the product data sheets show zinc and phosphorus levels you will see if it is sm (around or below 0.080 percent by wt) or SL (closer to 0.10 percent). Some are thicker than others, such as the Citgo 10w30 is 12 cSt at 100C, whereas Maxlife conventiona 10w30 is 10.5 (Maxlife Synthetic is 11.5 though).

A UOA on the Citgo Ultralife showed the high zddp levels, but I don't know if this oil is still SL or even that easy to find. The Maxlife I know dropped the zddp levels to sm ratings, but added moly at the same time. The Maxlife Synthetic I believe remains at the SL zddp levels.

As the miles pile up the best high mileage 5w-30 might become a 5w-40, then a 15w-40 and so on, as oil consumption goes up.