AMSOIL 5-30w

[rspeers]

In December I changed to AMSOIL 5-30w with 16000 on engine. Up to this time my oil pressure was always steady at any RPM and it didn't use oil. Was using DELO 400 15-40 with no complaints. Now my oil pressure is lower at any RPM after the engine warms up and in 1000 miles it has consumed two quarts of oil. I have looked under the truck to see if it was being rust proofed and there is no change from before. Also the engine runs alittle noisier and my MPG is down by 2 using a calculator, not the overhead guage.



Has anyone had this kind of change or is mine unique?



Any thoughts would be helpful. Oo.

 

[HC]

A drop in oil pressure would be normal with the thinner oil. Not much, but some.



I lost a little more oil when using 5W-30 vs thicker stuff, but nowhere near 2 quarts in 1000 miles. More like 1 quart in 5000+ miles.



On your mpg drop, do you calculate EVERY tank, or did you calculate some, and then maybe skip some, and then calculate it again after the oil change? If you haven't calculated it since say September or October, or if really cold weather hit your area in December, then the 2 MPG could be due to winter fuel or just plain colder temperatures in December. I see 1 to 2 mpg less whenever temps stay below freezing. So maybe you switched to the thinner oil as really cold weather was hitting; in which case it will come back up when Spring gets here. Also, exhaust brake use for warming during cold weather really drops your mpg; I notice you have an exhaust brake which you may or may not have owned last winter.



I'd keep checking oil levels very carefully on the next tank or two of fuel; if you really are losing more than 1 quart in 1000 miles then something is very wrong which goes far beyond just switching to a thinner oil. JMO, and post additional info as you trace this problem.

 

[kevincook]

I switched at 70,000 I did get 2 mpg more! I had thought you were to wait for at least 20000 before going to synthetic.



KC

 

[Red Rocket]

I don't know what to tell you about consuming 2 quarts in a thousand miles, but the 2 mpg drop could be a number of things, all the way from tire pressures to fuel...



As for the oil pressures, yes they drop a little as said sooner, but I have seen lots of oil pressure guages, not just diesels, and they all like to move some for different rpms.



I am running amsoil 5 30 hdd. I now have 6000 on the oil, got back a great sample a couple days ago, and haven't needed to add any makeup oil except what came out in the filter change at 4,000.



I have also heard it takes some time to stabilize when you change to synthetic, so maybe give it some time and see what happens. Good luck.



Nick

 

[John Berger]

I would have waited until at least 20K miles before considering synthetic. I didn't switch to synthetic until the truck had close to 50K miles. Monitor it and see if it stabilizes. If push comes to shove go back to dino oil and run it for another 25K miles or so. It can't hurt.



Did you use the engine flush prior to switching?