Chevron Supreme 5w30 or 10w30?

[Big Red]

Hey Guys
I'm considering switching over to Chevron Supreme motor oil after reading the positive remarks about it on this board. I went to my local Walmart yesterday and noticed they only had 5w30 Chevron Supreme in stock. My question is will the 5w30 hold up to stop and go traffic in 80-100 degree driving during the summer months or should I try to find the 10w30 Chevron Supreme? My owners manuel for my 1995 Nissan 4x4 V6 indicates 5w30 is the perfered grade all year round, although 10w30 is ok during warmer months.
Thanks

 

[mikemc]

Supreme 5w30 is made from a group 2+ base and has a good addative package. I think it would be fine for year round use, given reasonable drain intervals.

 

[YZF150]

Red, remember that they are both 30 weight oils when warmed up. You shouldn't see a lick of difference, although the 5w may thin out before the 10w under abuse.

 

[Big Red]

YZF150 and Ray H
Thanks for your feedback, both opinions are interesting.

 

[Ray H]

Red, UOAs show a tendency for 5W-30s to shear back to nearly 20 weight by 3,000 miles. Since the base stocks are 5 and 10 respectively, it would stand to reason that 10W-30 does not place as high a demand on the VI improver to maintain viscosity grade as does 5W-30. I run 10W-30 year around, but I live in a temperate zone here in southern California. Given your location in Baltimore, I'd argue for following Nissan's allowable recommendation of 10W-30 late spring through early fall, and 5W-30 late fall through early spring. The 10W-30 probably wouldn't show as much shearing tendency as the 5W-30 in hot weather use, and you'd still have the pumpability at startup your engine needs in cold weather.

[ May 26, 2003, 12:59 PM: Message edited by: Ray H ]