Is Stihl Ultra HP Oil no good?

[HansFranz]

I'm sure this has topic been hashed to death, but when I did a search, the newest thread I found was over 10 years old, so ... here we go again.

It seems like I've read here where people have said that the Stihl Ultra HP oil is crap. Am I remembering that right?

The reason I ask is, I recently bought a Stihl FS91R string trimmer, which comes with a 2-year warranty, and the dealer said they'd double the warranty to 4 years if I bought a 6-pack of Stihl Ultra HP oil bottles (enough in each to mix one gallon at 50-to-1).

I've been using Mobil 1 2T Racing Synthetic oil in all my 2-stroke equipment now at 40-to-1 for years with nothing but good results. I'm tempted to stick with that plan, but if this weedeater is gonna go belly-up, I figure I'd better at least have the Stihl Ultra HP oil in the 2Mix if I take it back to the dealer under warranty...

Kind of a weird deal on this one, because it's technically a 4-stroke motor but you run 2Mix fuel in it...I was very skeptical that it would have decent power, but everybody said the machine was real torquey, and sure enough, it is ... I'll be dammed if I understand why, though...I would have expected a 2T motor of equivalent size to have way more power...

Anyway sorry, I'm rambling...long story short, I'm real pleased with this weedeater, seems to be more powerful than any I've owned, and I've owned several over the years...

 

[OH_Varmntr]

Yes you're remembering that right. Do some reading in their warranty verbiage and see what is required for the 4-year coverage to be honored. Here is an excerpt from their policy where warranty won't be covered...

1. Any failure caused by lubricants not supplied or recommended by STIHL.

So what you said above...

I figure I'd better at least have the Stihl Ultra HP oil in the 2Mix if I take it back to the dealer under warranty...

 

[snobdds]

I use motomix. I have never had an issue with mechanical failure due to a lack of lubrication.

But if you ask others...I might as well put sand in the tank.

 

[farmer steve]

Haven't had a saw failure from using it in over 30 years. 1/2 of those years were at the dreaded 50:1.

 

[stihl sawing]

I used it for years, didn't stop using cause it was bad, stopped cause it was more expensive, and you had to get it at a Stihl dealer. been using Red armor for a while now.

 

[ZeroJunk]

The HP Ultra is good for the 4 Mix engines because it doesn't leave as as much deposit on the valve stems and seats.

That's it. Two cycle stuff use whatever you like. Plenty of good stuff out there that nobody will ever see the difference in.

 

[bwalker]

The HP Ultra is good for the 4 Mix engines because it doesn't leave as as much deposit on the valve stems and seats.

That's it. Two cycle stuff use whatever you like. Plenty of good stuff out there that nobody will ever see the difference in.

This. Ultra is good and was designed for 4mix engines. It's terrible in a 2 stroke engine.

 

[AnthemBassMan]

I just bought an MS261c a week or so ago. I did get a can of Motomix to extend the warranty. But once that can is gone, it’s going to be run on the same Amsoil Saber 40:1 mix that I run everything else on.

L8R,
Matt

 

[slowcar281]

Stihl ultra is only an FB rated oil so it doesn’t burn as clean. I ran it for years on a homeowner level and never had an issue with it at all. If you do use it regularly, I believe it’s designed to be used at 50:1

Some people swear by it, some swear at it and act like you are pouring sulfuric acid into the engine.

I never had any issues running it in my equipment. Only my blower was a 4 mix.

 

[Pjohnson]

I've used it for as long as I can remember, my 250 is over 25 years old. My 362 13 years old and my 4 mix weed eater 12 years old, haven't had any problems. That being said I'm thinking of switching to red armor, from what I see it appears to have less carbon build up.

 

[HansFranz]

This. Ultra is good and was designed for 4mix engines.

Well, crap. Sounds like I need another gas can so that now I'll have:
1. Straight gas
2. 2Mix
3. 4Mix

It's terrible in a 2 stroke engine.

Can you elaborate why it's terrible in a 2T engine? (Not arguing, just trying to decide whether I need to buy another gas can.)

Also, after this HP Ultra oil runs out, do I need to keep buying some kind of special oil for the 4Mix engine -- and keep two varieties of mixed fuel on hand -- or can I run my normal 2-stroke mix of Mobil 1 Racing 2T at 40-to-1 ? (Ignoring warranty concerns -- assume I will be out of warranty at that point.)

Or...Option #2, use my normal Mobil 1 Racing 2T oil but at 50-to-1 instead of 40-to-1?

FWIW, according to the Stihl manual (this is from an online pdf I found; the printed manual is slightly different in that it just says to use a 2-stroke air-cooled oil, but doesn't list any API or JASO specs):

"If you mix the fuel yourself, use only
STIHL two-stroke engine oil or another
high-performance engine oil in
accordance with JASO FB, JASO FC,
JASO FD, ISO-L-EGB, ISO-L-EGC or
ISO-L-EGD."

and my Mobil 1 Racing 2T full synthetic oil says that it's "JASO FC" ... so I'm assuming it's OK.

Option #3: I have a 4L jug of Motul 800 Racing 2T oil and I've heard that when used in chainsaws, Motul 800 stays "wet" inside the saw ... so maybe using a 50-to-1 mix of that in the weedeater might be good if the concern is carbon buildup. According to Motul, "Motul 2-Stroke engine lubricants meet JASO FD and FC specifications under the latest standards, except for 800 racing motorcycle lubricants which are above existing standards."

 

[stihltech]

If you read it on the internet it must be true.
However, not seeing failures in the shop from any stihl mix.
Must be lucky I guess.

 

[bwalker]

Well, crap. Sounds like I need another gas can so that now I'll have:
1. Straight gas
2. 2Mix
3. 4Mix



Can you elaborate why it's terrible in a 2T engine? (Not arguing, just trying to decide whether I need to buy another gas can.)

Also, after this HP Ultra oil runs out, do I need to keep buying some kind of special oil for the 4Mix engine -- and keep two varieties of mixed fuel on hand -- or can I run my normal 2-stroke mix of Mobil 1 Racing 2T at 40-to-1 ? (Ignoring warranty concerns -- assume I will be out of warranty at that point.)

Or...Option #2, use my normal Mobil 1 Racing 2T oil but at 50-to-1 instead of 40-to-1?

FWIW, according to the Stihl manual (this is from an online pdf I found; the printed manual is slightly different in that it just says to use a 2-stroke air-cooled oil, but doesn't list any API or JASO specs):

"If you mix the fuel yourself, use only
STIHL two-stroke engine oil or another
high-performance engine oil in
accordance with JASO FB, JASO FC,
JASO FD, ISO-L-EGB, ISO-L-EGC or
ISO-L-EGD."

and my Mobil 1 Racing 2T full synthetic oil says that it's "JASO FC" ... so I'm assuming it's OK.

Option #3: I have a 4L jug of Motul 800 Racing 2T oil and I've heard that when used in chainsaws, Motul 800 stays "wet" inside the saw ... so maybe using a 50-to-1 mix of that in the weedeater might be good if the concern is carbon buildup. According to Motul, "Motul 2-Stroke engine lubricants meet JASO FD and FC specifications under the latest standards, except for 800 racing motorcycle lubricants which are above existing standards."

It's a FB oil which is a early 80's quality level. In addition it's an ashless oil, like a boat oil and works poor in air cooled two strokes.

 

[bwalker]

If you read it on the internet it must be true.
However, not seeing failures in the shop from any stihl mix.
Must be lucky I guess.

Uses your eyes and Google up some picture evidence. No other MFG says runninga 1980's quality oil is reccomended.
That and it's ridiculously expensive given it's low quality.

 

[HansFranz]

Ultra is good and was designed for 4mix engines. It's terrible in a 2 stroke engine.

Can you elaborate why it's terrible in a 2T engine? (Not arguing, just trying to decide whether I need to buy another gas can.)

It's a FB oil which is a early 80's quality level. In addition it's an ashless oil, like a boat oil and works poor in air cooled two strokes. ... That and it's ridiculously expensive given it's low quality.

OK, thanks. I appreciate your help.

I was also surprised to read (on the label) that although it's "fully synthetic," it's also "biodegradable."

 

[slowcar281]

A couple of years ago I emailed Stihl asking why every other major saw manufacture recommended an FD rated oil and Stihl uses an FB which is all but obsolete.

The guy responded with some canned response about how the additives in an FD rated oil aren’t necessary for protection in a 2 cycle engine..etc and all that’s needed is what’s in an FB oil.

I find it funny that the Stihl’s “ mid tier “ HP super oil is rated FD. They haven’t sold it here for probably a decade or longer, but they still sell it overseas, and sure enough it’s still FD rated.

 

[farmer steve]

Well, crap. Sounds like I need another gas can so that now I'll have:
1. Straight gas
2. 2Mix
3. 4Mix



Can you elaborate why it's terrible in a 2T engine? (Not arguing, just trying to decide whether I need to buy another gas can.

Never have to many gas cans.

 

[stihlaficionado]

It's horrible...I'll take anything you don't want to use

 

[gggGary]

Same deal on a 261 I just got, double warrentee but I've been running it for years a wide variety of Stihl saws. from 028 to 066 and a mess of 4mix trimmers saws etc. have never cooked a cylinder.
OK long ago a 390 buried 25" bar, bucking up a 42" elm with a dull chain on a tornado cleanup trip gave it's life. Not my premix. I got smart after that, carrying my own sharpening equipment and changed to pro quality saws.

 

[snobdds]

I think the additives in the gas have a larger impact than whether an oil is FB or FD rated.

But that's just me...