valvoline synpower 5w-40 any good?

[Norm Olt]

Originally Posted By: CATERHAM
Originally Posted By: shDK
I drive it mostly highway with speeds between 120-140 km/h. The fuelconsumption is pretty close to what mazda says i should use.

Apparently 20 oils is not verry popular here. It is considered to much of a compromise in bennefits of the fuelconsumption rather then protecting the engine. 5-40 is officially aproved by mazda denmark.

With speeds that low you the ideal lubricant choice would be the lightest oil Mazda has spec'd for your engine; namely, a 0W-20 for year round use. Heavier 0W/5w30 or 5W-40 oil grade will not provide any greater engine protection.
So the question comes down to cost an availability.
If a 5w30 is significantly cheaper then use it; the fuel economy hit will not be significant particularly during the summer months. I would not recommend the 5W-40 grade, even if it was cheap as the 3-4% fuel economy hit over a 0W-20 should negate any cost effectiveness not to mention the other performance negatives.


"3-4% fuel economy hit"???????

Sorry: I just don't believe it. Pure speculation. Pie-in-the-sky.

Cheers!

p.s. 140 kph = 86+ mph This is some how "speeds that low"?????

 

[CATERHAM]

Yes I agree a 3-4% fuel economy difference between a high VI 0W-20 and 5W-40 is on the conservative side.

86 mph is loafing alone in a Mazda 6 and will not raise oil temp's above normal.

 

[shDK]

Fuelconsumption is not my biggest worry. But will using a 5w-40 harm the engine in any way ?

 

[dparm]

Originally Posted By: shDK
But will using a 5w-40 harm the engine in any way ?



No, not really.

 

[CATERHAM]

Originally Posted By: shDK
Fuelconsumption is not my biggest worry. But will using a 5w-40 harm the engine in any way ?

Not really particularly though the warm summer months.
Most engines are very tolerant of running heavier than necessary oils. I don't care about the slight reduction in fuel economy either, for me it's the noticeably increased oil drag (engine sluggishness) when the oil is cold that I don't like.
If you still plan to run this oil in the winter, just make a concentrated effort to keep the rev's down when the engine is cold.

 

[shDK]

Okay.. i think i will drive it trough summer and when changing before winther i will put in some 5w30 fully syn. Maybe valvoline