10W-40 Valvoline Maxlife really that bad?

What is wrong with the 10W30 recommended by the manufacturer? That is what I use in my Jeep and in my Suburban in Colorado, and it gets pretty darn hot here in the summer. The thermostat fixes the operating temperature at a set value anyway.

Earle

whats wrong with 10W40? I've been using it for 12 years (valvoline the whole time and maxlife when it can out) 165 K miles so far.....I also use it in my 5 speed, per the request of the reman company.....no problems, shifts great works great.

A thicker or heavier weight oil can cause more problems than a light weight oil, especially when the light weight is what is recommended by the manufacturer. Greater load on the oil pump, less flow to the bearings; the following is from

who spent decades designing aircooledVW engines for the strip and street. "Another concern is the weight of the oil. Remember, the heavier the oil, the less it lubricates. We run 20 weight in our race engines and 10-30 weight in all street engines. Only if the temperature is constantly above

80-85 degrees would I consider 10-40 weight. 5-30 should be used when temperature falls to below 45 degrees. For freezing temperatures straight 10 weight would be my choice."

Earle

I use it in my 89 Sentra. It has 165k on it, with no engine problems at all. It only burns 1/2 qt every 3k miles.

So, using this fill of 10W-40 until the next oil change 3,000 miles away should be no big disaster, I guess.

Perhaps, the 10W-30, recommended in the manual is still most likely the most appropriate, even in a tropical climate.

Approximately 11/12/03 15:38, Robert Goldpalm uttered for posterity:

No issue at all.

Go figure.