Dr Diesel can you explain why some of us have had more oil usage and leaks with the synthetics in higher mileage vehicles versus the regular oil in the same weight or similar.I was just wondering,thanx

 

Hello back Dufrain... and thanx for your confidence in asking a difficult question... I hope I retain my credibility with my immediate HONEST answer which is... "I don't know"... at least not sure enough to wing a confident answer... at this moment I could only offer a SWAG (Stupid Wild-A__ Guess)... and I won't do so...

BUT...
A.) Although retired, I still have my contact (Jim) right in the heart of a major oil Co. reasearch center, and I'll call him and see what he might offer... (might take a week or so)... and respond...

Another BUT... Before I call Jim... I need more info...
B.) In order to generate an intelligent answer, CAN YOU BE MORE SPECIFIC ABOUT YOUR APPARENT INCREASED CONSUMPTION with the synthetic... I already see you have a 330,000 mile ragburner, but please tell me specifically...

1.) What is your consumption / usage with what brand and viscosity of synthetic ???...

2.) What is your consumption / usage (after apparently switching) with what brand and viscosity of traditional oil ???...

3.) Were the driving conditions the same ???...

(If indeed the synthetic was a multi-vis, and the traditional was a straight 30 or 40... that may be the answer right there... Even tho' ideally the multi-vis is designed to hold the high number viscosity at operating temp., there real world results are often that the same number straight grade holds up a little "tougher"... which is exactly why Detroit INSISTS on the straight viscosity (40 rather tham 15-40) for its 2-cycle models, due to power on every stroke (with no intake stroke to cool the piston top) results in an overall average higher cylinder temp)... but let's not conclude anything until you accurately answer the 3 questions above...

Cheers... ...Ted

 

I agree with you on this subject.... I've have or had several Dodge trucks and Cars (Sig below) and used both syn and dino juice. I saw about .8 to 1 MPG change in performance and yes it got dirty just as fast! So I will stick with my bulk dino juice... It all about changing the oil regular and getting the dirty oil out.... Enough said!

 

Thanx for the reply Doc.I dont want to Hijack this thread too much but i thought it would be some good info for us all.


1.) What is your consumption / usage with what brand and viscosity of synthetic ???...

With Mobil1 synthetic 15w50 I was having to add about 2 quarts between 3000 mile oil changes on a 4.3L V-6 in an astrovan with 150,000 miles on it.

2.) What is your consumption / usage (after apparently switching) with what brand and viscosity of traditional oil ???...

On the same vehicle, before and after switching to the synthetic, using 20w50 regular mobil oil I didnt add any oil between oil changes ever to this day and the vehicle has 180,000 on it now.

3.) Were the driving conditions the same ???...

The driving conditions have remained the same before and after the temporary switch to synthetic. I havent tried synthetic in hi mileage vehicles since then,but others here are having good luck with it in their diesels.thanx for the help.

 

First of all my father ran Dello 100 in his dodge( cummins) the entire time he had it . He never had a bit of trouble with the engine. It did not hold as good as oil pressure as my truck does(95 dodge, cummins). I know that Iwill take some heat here, but I use 15-50 in my dodge year round here in Texas. The oil is Mistic made in OK. I have used it for years. I have used it in my welder, back hoe, tractor, and even a miata. I ran it in my vw diesel for 250k and switched to 30 weight and it leaks like there is no tomorrow, now. I would not have used it but it was free. I was given two barrells of it. The 81 vw and a honda lawn mower is the only thing that I would use it in.
Many years ago I got talked into helping a friend? as he needed help. We drove a 454 one ton to Mississippi and it had a huge compressor on the mini float in tow, about 30klb. I ran it flat out all the way. It used 3 quart of 15-50 going down and running back, unloaded about 9 or 10 quarts of 30 weight pennz. We could not pass a station but the truck would run and finally after several tire falures the fun went away. I dont drive like that any more and I sure dont wont a 454 chevy.
I ran 15-50 in a camaro that had a 350 enging a long time ago and I would run it from 4k to 6.5k with 3.54 gears for a hours.
It was a warmed over 350 that had the ability to pull to 6200 in high gear. I did not ever have any problem with the engine as long as I used 15-50. I had camshaft( lobe wear) with penns 40 GT oil. No other changes were done except to change to 15-50 and no more camshaft problems.
I use 15-50 in a toyato 4x4 turbo diesel for years and several 100k miles and never had a problem, finally gave it away. Mistic is what I buy, how ever most will laugh and call it snake oil, but not me. Jim

 

I have used that mistic before ,they used to have it a rural king,its a local farm store chain.I liked it,i used thier gear oil also.

 

Too reply back to your question of oil....

1. Phillips 66 - 15W-40 ($33 for 5 Gallons!)
Tried - Castrol 10W-40 Syn & Rotella 15W-40 ($50-60 for 5 Gals)

2. "0" quarts on all vehicles in signature below with dino or syn

3. On the 96 Dodge it gets about 10,000 Miles a year
On the 02 Dodge CTD it gets about 22,000 Miles a year.

No real changes fuel milage changes about 0.8 to 1 MPG for syn... Not worth it!

 

I have ran the Rotella in several trucks as well as the ones in my sig. I have a real close friend who uses it in his ctd, and 12 Peterbuilts. No oil related probs so far. I'll be using the Rotella w/ regular changes for a long time to come.
Oh and it does get warm down here.
jmho
wayne