20K approaching and here I go....
Want to use Syn oil in 07 5.9, drive approx 15k a year, pull 10k trailer about 6 times a year. Which Syn oil and weight to switch too ?????

 

I am not a dealer, but I do use AMSOIL 15/40 AME Synthetic and have had great results. I Switched over at 15,000 miles or so.

 

Rotella 5-40 synthetic is $16.24/gallon at Walmart. Cold starts are alot easier and quieter compared to 15-40. I also got a slight increase in mpg.

 

depends where u live and how hot/cold it gets. If you live in Alaska I would got with thinner, in death vally thicker. If you live like most ppl in the middle just go with the factory weight, remeber synth as a higher flash point so it can take higher temps.

 

If you go with Amsoil you can use either there 15w40 or the 5W30 HDD. I use the 5w30 HDD year round and our temps go from -30 below zero in the winter to 90 degrees or higher in the summer.

 

Any class 4 synthetic.(a real totally synthetic oil, the law allows petro comp. to call an oil synthetic if it performs at same level, even if it is dino oil, go to Bobistheoilguy.com and read) Personally, down here and in Tenn, I wouldn't use a 5W. I would go with 15-40. For example, this past summer we had a week of 100 degree highs, so you can imagine how hot it is over pavement. My 15-40 does fine even in low teens (Class 4 synthetic), and in summer if I am driving or pulling something, and it is 95 degrees or 110 over asphalt, I feel better having the 15-40 in it. JMO I'm no expert. Hope this helps.

 

I run my truck all year around with the Valvoline Premium Blue Extreme (5-40 synthetic). I live in Phoenix, 120* in the air is normal!!


Aaron

 

Any syn oil will give great service if has correct cert. The engine will never complain. Would stay away from 5-30w though.

 

You may not like my 5w30 HDD oil but what I use is much better then Rotella 5w40 synthetic.

 

If your concerned about engine oil then you should also consider the lubricity of your fuel. 5% biodiesel raises lubricity considerably. Perhaps to the level of high sulpher diesel. Maybe more. I use it when the weather is above freezing.

 

5w-40 is still 40w, just like 15w-40. It just flows easier in cold weather. However I would be weary of using 5w-30 in hot (often over 100 F here with heat indexes over 110 F in the summer) unless I didn't tow anything. Which I do. No scientific fact behind this, just my opinion.

Bill
05' QCLB 4x4 CTD

 

Prove it.....

 

Rotella 5w40 Synthetic, If you have an Autozone, its cheaper than Wally World.

 

Really? Here around the Temple/Belton area Wally World is over a $1 a gallon cheaper. $16.24 at Wally World and $17.29 at Autozone.

Bill

 

You are correct. But I think a 5W-40 vs. a 15W starts the base oil with a
5wt vs.15 and then they both get up to 40 by viscosity index improvers.(I am relying on memory, so I could be totally wrong) I would just rather start with a 15 wt than 5 wt to keep metal off metal. Very hot here even without heat index. Probably doesn't make a crap, just makes me feel better and JMO also. I just like putting a 15-40 class 4 synthetic that is proven in marine diesel where they are put to severe duty. Again, I could probably go to WallyWorld and get their cheapest diesel oil and as long as it was rated CI or even CJ it would work as good as the expensive stuff I get. I am going to do a UOA soon and see if I can just start changing my oil in my bug diesel and my truck once a year as I rarely put over 12-15k a year on them.