Synthetic vs Conventional

[Brent_G]

Hey all,
Tonight when i was changing alts in my car, I started thinking about if syn oils really make an engine that much cleaner inside. Since one of our tow trucks was down having new bushings in the autoload, and i needed to flush brake fluid in my truck I figured I would compare.

Quick overview of the trucks. My truck is a 2001 Ford f150. 5.4 v8 with currently 140k on the clock. The wrecker is a 2001 f350 with v10 also with right at 146k on it. They are great to compare because the milage is so close, years are the same, both have either been on conventional or syn there whole lives, same basic engine, and pretty close to the same driving habits.This will be 3 seperate posts because for some reason the forums wont let me scroll down to see what i type.

 

[Brent_G]

First pic is the f350

Truck has been serviced since new every 3K never more by driver using napa gold filters and napa convetional 10W30. 3 pvc replacements and is 80% town driving with a few calls a week sometimes up to 60 miles out. Some idle time mixed in. varnish visable on all areas, and buildup on top of head, on cam and into the fill tube. and truck is always ran for usually 45 minutes to an hour at a time. Has quite a few ticks at idle and a lifter that also ticks while driving

 

[Brent_G]

F150


This truck has seen mobil 1 its whole life, mainly 5w30, with last fill of 0w30 and currently 5w20. Only 2 pcv changes and has been short tripped alot more than the other and alot more idle time. Sometimes has idled over 10 hours during a extremely cold night (-40 or colder). 5-6k oci with a few touching 10k. maybe 40k miles of hwy use pulling a gooseneck trailer to and from auctions. As you can see there is even condensation built up in the fill tube. light discoloration on all surfaces. Truck has no ticks, and runs like new. used right around a half quart per oci. And this isnt a mobil 1 only thing. I checked our 2004 ford freestar van, that hauls parts 300+ mile trips every week and takes workers to airports, sometime over 1k trips. I never got a picture because i felt these 2 where a better comparison. the van is sitting at 200k miles, only used syns on sale, and 10k oci and it looks about the same as the f150.

Also sorry about the walls of text but i felt the extra info helps
I know the little extra cash is worth it to me now

 

[bmwtechguy]

Hard to argue with that. But I have seen some very clean high mileage engines that were run on conventional oils from the beginning, but with religious 3k mile oci. I do like the extra margin of "safety" for the occasional super long oci that happens accidentally when life just gets busy. I also like the potential for less ring land deposits when using a synthetic oil with sensible oci. I know for a fact in my experience that engines that have been run consistently on synthetic have higher and more even compression way down the road at 200k miles than those run on conventional oil.

 

[Brent_G]

I agree. I have also seen quite a few clean engines on dino, my friends honda was over 100k and looks about the same as my ford, but he did 2k oil changes and hondas are easy on oil. And these 2 trucks are just something to compare, they had similar driving patterns, but are still 2 different engines, in trucks that work was the priority. Main reason my truck has been on syn is because of the sometimes high oci. i would not have trusted our driver to change oil, im quite suprised he could figure out how to put gas in and start it, let alone change oil. But he was always on time and no accidents, better than some

 

[ARB1977]

Synthetic will keep engines cleaner in the long run with longer drain intervals.

 

[aquariuscsm]

The Mobil 1 engine looks brand new!

 

[tig1]

I've used M1 oils for 33 years and all of my engines have stayed very clean and have never shown signs of wear as in the way the engine ran. My 96 Merc GM 4.6 had 218K on it when I sold it and it still looked new inside. That's with 10K and sometimes longer OCIs.

 

[RacerE7773]

Originally Posted By: aquariuscsm
The Mobil 1 engine looks brand new!

It does at that. I had M1 in my Tuarus but it got changed due to a fuel problem after the problem was repaired. Right now has 5w20 Castrol due to $ issues, but hope to change back to M1 next change in March.

 

[rjacket]

While the engines might be different, Ford would have had the same service interval guidance for both.

What's interesting is that clearly the truck on synthetic went way beyond the 3000 mile severe service interval and looks like new, while the truck on conventional met the 3000 mile severe service interval and doesn't look like new.

One question I have is at what mileage did 200 hours of engine operation come up? One of the severe service categories requires the engine oil to be changed at 3000 miles / 3 months / 200 hours whichever comes first. Be interesting to see if you met this with the conventional truck.