amsoil 15-40 vs 5-30.... need opinions ?

[PZicha]

Anyone that has tried them both please give me an opinion on which you prefer . I live in central Alberta and am coming up on a oil change soon . I am using Amsoil 15-40 but with winter coming soon I’m looking at the HD 5-30 . I also have a oil pan heater wired in with the block heater so getting quick oil pressure at start up is not a problem with the thicker grade... ... .

 

[BarryG]

PZicha:

I have used both. I originally started out using the 5w30 and loved it especially in the winter. I switched to the 15w40 this past spring really for one reason. I do a lot of driving in the desert southwest, towing or going very slow (read as hot) over rough roads and the old days of 10w40 just kept nagging at me so I switched to the 15w-40. I have not noticed any difference in mileage or performance of the oil, just a little more piece of mind. I know, I know get with the times and forget about the old ways. One thing I did notice was that I seem to have less blowby coming from the breather tube judging from the spots on my driveway. Not that it was ever that bad maybe ten single drips but I don't think I have had any more since I switched. Could be that the rings are just seated better with the higher mileage also. I can say that if I lived in Alberta I would use the 5w-30 no problem.

 

[JJW_ND]

5W30!

I run both and the 5W30 was noticable better for cold weather starts. I also notice a slight increase in MPG. I did notice MORE blow by with the 5W30 over the 15W40. You might notice a slight drop in oil presure especially when things are really warmed up. Nothing to worry about. I ran it over 70K miles. It did just fine.



I am currently trying Mobil 5W40 to see how it does.



jjw

ND

 

[HC]

I've used the 5W-30 before, am now using the 15W-40. In my warmer climate, I worried about using 5W-30. The wear analysis results didn't show a clear advantage to either one, but the 15W-40 is considerably less expensive. If I were in Alberta, I would try the 5W-30 and Delvac 1 (5W-40), and chose between those two.

 

[EMDDIESEL]

I am running 5W-30 synthetic in my 01'. Truck runs and starts great, year round.

 

[PZicha]

I would love to run it year round but my biggest worry is when I,m towing our 5th wheel and the oil film protection under load . Coming from the old school I find myself struggling with new idea,s ... ... But I always have an open mind

 

[fest3er]

Originally posted by PZicha
I would love to run it year round but my biggest worry is when I,m towing our 5th wheel and the oil film protection under load . Coming from the old school I find myself struggling with new idea,s ... ... But I always have an open mind

Check your service manual. My '98 SM says 10W30 is good for -23F to 30F (with block heater) (-23C to -1C for you metrically-inclined folks). 15W40 is good for 10F (-12C) on up. That said, I've been using 15W40 Diesel & Marine year 'round for 50K miles now. Both here and when I lived in No. IL. Analysis has never showed bad effects. But, YMMV.

OK, I've searched and can't find the temp range Amsoil synth is good for. Maybe someone else will chime in.

Fest3er

 

[hammersley]

Check out thread.....

http://216.235.147.117/forums/showthread.php?s=&threadid=55948 on Valvoline Specially formulated for Cummins 5w-40 Synthetic

 

[Vaughn MacKenzie]

I ran both 15W40 and 5W30 Amsoil, I had noticeably better oil analysis numbers with the 15W40. I towed very little, but the climate here can get very hot (113F this summer) which I'm sure is too hot to be running the 5W30.



If you want Year Round protection I recommend the Delvac 1. That is what I finally switched to and I like it. First oil analysis results were the best I've had with any oil in the wear metal counts.



The Delvac protects like a 15W40 in heat and pours like a 5W30 at -60F. Best of both worlds.



Vaughn

 

[Champane Flight]

All you ever need

All you ever need is the 15-40 Amzoil marine. It will give you great protection and superior lubrication at almost all temps. If you are in a climate that is -50 regularly, I would go to the 5-30 Amzoil. Even at those temps with a pan heater and a water heater, you don't need the 5-30. I have started with temps down to -35 with NO heater and had very little oil pressure delay. I do not like to do it, but sometimes have no choice. Amzoil in my opinion outperforms every synthectic out there.