Just had to post quick about my synthetic oil change. Truck had been sitting since saturday when it was about 60 out....since then the temp has fallen dramatically down to -5 yesterday and about that cold this morning. Well went out to start the truck just now and she fires right up no romping no dying, no nothing but starting. Have to keep in mind I didn't have it plugged in either just because I wanted to give it a good test and I have to say it passed with flying colors. I was a bit sceptical about the synthetic making any difference but there was just too many positives said here about it to ignore. So if anyone else may be wondering just go ahead and do it.

 

I agree. I think the difference between $9 a gallon for dino oil and $18 for synth. is worth it for just that, ease of cold starting.

 

When I started up my 7.3 at 28 F it had the romps also. I switched to Shell 5w40 full synthetic. Now it starts up faster and no romping. One thing I did notice. On the oil change from dino to full syn the engine was started up to check the filter for leaks. After about 5 minutes of running the engine noticeably quieted down and ran smoother. After a cold start up it moves quicker and easier. I think I will stay with the shell syn and move oil change freq to 10000 miles but change the filter and add 2 qts to top off at 5000.

 

I'd get an oil analysis first just to see where you stand on change intervals. You might be healthy enough to just go to 10K without any worries.

 

I just changed my oil to synthetic and it went from almost 60 degrees to about 15, so we will see how ti goes, sounds like it should be good.

 

Glad to see it worked well for you, My schaeffers works great for me during the cold spells.

 

I switched to syn a couple changes ago and love it. Will not go back to dino.

 

Glad to hear schaeffers is working good that is what I just put in

 

Today is the first day that I have driven the truck since I changed the oil on Saturday and I have also noticed the truck being quite a bit quieter and much smoother on idle and a little bit smoother and quieter running down the road.

 

Same thing I noticed but it is hard to measure and explain to someone else. But I drive the truck often enough that I notice it also. What I really found interesting was during the oil filter leak check with the engine running I actually heard it smooth out and it has been running smoother ever since. My guess is the fuel injectors are being lubricated better allowing for better fuel distribution and the valve lifters are also running smoother. But then only my speculation vs imperical data.

 

Many of you may already know this, but I would like to explain why every one is seeing their trucks start better in cold weather running the synthetic vs dino. First off an oils viscosity is defined as its resistance to flow. That is especially important to remember with thinking about oils no matter what kind of oil, whether it be motor oils, hydraulic, or gear oils.

Lets look at a 15w40 oil whether is be a dino or synthetic. The w stands for winter. The base stock of that oil is a 15 weight. The oil companies then add polymers to this oil, that when the temp. rises it changes to a 40 at operatiing temps. This is called a multi-viscosity oil.

Now lets take a look at a 5w40. The base stock of this oil is a 5 weight. It also has enough polymers in it to change it to a 40 weight at operating temps. A 5 weight oil will flow 3 times faster at start up than a 15 weight. Since our trucks are driven by oil pressure, our trucks will start and run much smoother than on the 15 weight at start up and still have very good protection at start up.

 

they also start easier with 15w40 synthetic than 15w40 dino

 

I agree with you, but could you please explain.

 

Yeah it's not that extreme here ever but synthetic doesn't have such a drastic change with temp as regular dyno oil. The only benifit I really get to see is the longer service intervals. But that works for me since I put a lot of miles on it in such a short amount of time. If it weren't for that I would get to change my oil every week at times.

 

The COF is lower. Coefficient of Friction is the effort of one surface to move across another with a given amount of pressure. This will be less with synthetic in addition to lower viscosity. COF, film strength, and viscosity are critical improvement areas with synthetic.

One area that may or not be better is the shear strength (EP = Extreme Pressure) This would be in ring and pinion gears with sliding force. With MDS in the dino oil the shear film strength was very high. Some synthetics even with low COF didn't have the shear strength. However this has improved significantly in the past few years.

Comparing a 5w40 syn to a 15w40 for viscosity won't show much difference in viscosity. Granted there is some,, however reduce the COF and lower viscosity with synthetic oil over dino oil will make it easier to turn the engine over. The Injector pump will also need the lubricant to have both characteristics,, therefore reducing the romp on start up.

My $.02

My bottom line,, Shell full syn 5w40 works for me so I will keep using it.