trip75

I'm wondering the difference between Mobil 1 15w-50 synthetic oil and mobil 1 15w-50 Tri-synthetic oil. The difference is almost $2 a quart. Any suggestions, does the regular synthetic oil work good in our cars?

tlee

Lots of Oil related threads on here, try the search function. One of the real oil guru's Doug Hillary did say the newer formulation Tri Synthetic is a very very good oil, many of us have been using it, I personally would only use this newer formula, some complaints were evident with the earlier formula under tougher conditions... FWIW DYODD YOMV...

Tony

I cant seem to find 15-50 anywhere these days.

TeufelHei

Yeah...I've got the same trouble here. I was using 5w-40 M1 Truck/SUV formula on Doug's recommendation, then they stopped selling it. Bastards.

John Veninger

Many vendors are feeling a supply pinch.

ew928

Was surprised to find the local store with Mobil 1 0W-40. Porsche's new recommendation
oil grade. (Strauss Auto on Rt 46 in Joisey)
Can find Mobil 1 (Truck/SUV and regular) 10W-30 everywhere.

Ernest (NYC)

hinchcliffe

I found Mobil 15w-50 at Wal-Mart in gallo jugs for just under $20/gallon. Of course thw Wal-Mart at Watkins Glen didn't have it and I ran out, luckily CarQuest in town had it.

SwayBar

Mobil 1 0W-40 has the higher European shear-strength rating.

Here's a report/dyno showing switching from a conventional 20W-50 to Mobil 1 Tri-Synthetic 0W-30 was worth 10 hp and 15 ft-lb of torque:

http://www.carcraft.com/techarticles/15378/

John Veninger

Don't use a 0W-30 in a 928 unless you put a new chevy motor in it!

MGW-Fla

I tried about five places a few weeks ago looking for Mobil 1 15/50 in the gallon jugs. It has been pretty much all that I use in all my vehicles. Even in my 88 Jeep with 223k miles on it without any problems. The WalMart near my home showed a spot on the shelf for it, but was out. I've bought it there before. The WalMart near my office didnt even have a spot on the shelf for it, or in quart size either! Both are Super WalMarts so that was odd. Only found it in the quart size at Target & PepBoys for $5-6 a qt., too much $$ for 8 qts., thinking I'd find the gallons somewhere.

I ended up using just going with the Castrol reg. oil in the 15/50. After reading the comments a few weeks ago about leaks showing up after using synthetic, maybe it was fate for me to not find it. Would of hated to have any leaks show up a few weeks before SITM. Also, I wonder with the heat here in Fla. if the 50 weight is more impt than being synthetic & using a 30 weight, always thought it was anyways.

Think I'll stay with regular non synthetic for a while in my shark & just plan on changing it more often. Does Mobil even make a regular oil? Or are there any brands preferred in non synthetic for a 928? As long as I can get it in the 15/50 weight.

unit

Im not expert and dont claim to be but what does synthetic oil really mean???
As nobody ever can explain to me why its so different???
Its oil and it comes from the ground right?.
I think its a marketing clever marketing tool.
Ive also heard mixed reports fabout synthetic oils in 928's and mobil 1 being too thin and causing wear.
I would be interested for someone to try and set me straight.

cheers
Sam

SwayBar

Well, get straightened out by reading the link in post #8!

hinchcliffe

I was using 15w-40 and getting a hot oil pressure of between 2-3 and with the 15w-50 I get just over 3. I'm happier with that.

Syntheic oil is basically dino oil with extra additives that mother nature couldn't add in. Read the link, you'll learn alot. Comparisons between dino and synthetic at the same grade show huge differences when cold and hot. Kind-of crazy. And no, it will not cause more leaks, but it may clean the old oil that was compacting into a leaking area and start to leak that way.

Bill Ball

Synthetic is dino oil with additives? That would be partially synthetic. I know the use of the word synthetic has been bastardized, but we need Doug Hillary to step in. I think that Carcraft article is a little loose with the facts.

mark kibort

the difference is the time it takes for the #2 and 6 bearing to fail. Tri synthetic takes 3 times as long.

try redline or amzoil.

mk