Which weight synthetic oil?

[VT365]

First 50 hrs service coming up on my Kioti CK30HST, I've always used Amsoil synthetics, and need a recommendation on which diesel rated oil to use.

 

[MikePA]

First 50 hrs service coming up on my Kioti CK30HST, I've always used Amsoil synthetics, and need a recommendation on which diesel rated oil to use.

What weight does your owners manual say to use?

 

[VT365]

10W-30 or 10W-40

 

[DieselPower]

You don't have your location in your profile. If your in a colder area use the 10W/30, hotter locations use the 10W/40. Your owners manual should spec what temperature range each viscosity is good for.

 

[dutchman56]

Go with manuel recommendations as normal or synthetic oils are rated the same for viscosity. It is measured at 40 C or 100 F. What you get with synthetic oil is a better viscosity index number (0 to 200) with means it will not change its viscosity as much as conventional oil with temperature change.

 

[DieselPower]

Actually that's not correct. Temperatures used for multi-viscosity oils are taken at 40 deg. C for the cold temp viscosity and at 100 deg. C for the hot temp viscosity. So a 10W/30 acts like a 10 weight at 40 deg. C and acts like a 30 weight at 100 deg. C. There is also no difference between synthetic and conventional as far as viscosity is concerned. If it's a 10W/30 that's what it is. What you are probably thinking about are synthetic's like 5W/40 when compared to 15W/40 conventional. Thre is a difference there, the synthetic acts as a 5W at 40 deg. C and the conventional is 15W at 40 deg. C.

 

[kenmac]

First 50 hrs service coming up on my Kioti CK30HST, I've always used Amsoil synthetics, and need a recommendation on which diesel rated oil to use.

You are using an excellent oil ( Amsoil) Just Choose one of the weights that your owners manual recommends & you'll be good to go


I forgot to mention . You know Amsoil isn 't API certified don't you


Wonder how they (Amsoil ) has been in business for so long ?

Selling junk oils that aren't API certified

 

[IH3444]

My understanding is that multi-viscosity oils do not thicken as oil temperture rises. A 5w-40 oil, is an oil that has flow as a 5w oil when cold, but also protects as a 40 weight at operating temperture. A 15w-40 oil has flow as a 15w at cold tempertures, but it also protects as a 40 weight at operating tempertures. The "w" denotes both as winter oils, with additives which improve their cold temperture flow ability.

Once again.......
Lifted from another thread, in the Ferrari forum.....don't know if it's true or not, reads interesting.....

"A bit of information directly from a shell engineer. Note that at the end he states that the base stock in Rotella T 5w-40 synthetic (available at walmart for $14 a gallon) ,Shell Helix(Ferrari dealer $16 a quart), and Ferrari's formula 1 oil cocktail is the exact same thing minus different additives. Is the highly rated Rotella T synthetic 5w-40 another credible alternative to overpriced Helix? After all, the Rottela t does meet and far exceed all current testing standards (SL, Sj, etc) not to mention an incredible viscocity index of 178 degrees c (mobil 1 0-40 is 168 c).

"It is true that ROTELLA T Synthetic is Group III (not PAO) based, but you must keep in mind that not all Group III base oils are created equal. ROTELLA T Synthetic is made with Shell's XHVI base oil, which unlike other Group IIIs does not begin as distilled crude oil, hence of all Group III base oils, XHVI is truly the only one that can legitimately be called "synthetic." XHVI is a wax isomerate, meaning that it is made from the slack wax removed from distilled crude in normal solvent dewaxing. This slack wax is catalytically transformed (isomerized) and hydrofinished into a chemically pure base oil which rivals PAO in virtually every category. There are other "synthetic" oils out there based on Group III, but Shell's is unique in that it uses XHVI base oil. Chevron and Petro-Canada produce Group III base oils that come close to XHVI, but even though these oils are all hydroprocessed and utilize the same type of isomerization technology employed in the making of XHVI, they are not the same thing. Only XHVI is made from pure petroleum slack wax and its CAS number is 92026-09-4. The CAS number for the more typical all-hydroprocessed Group III base oils is 64742-54-7. If you want to know what your "synthetic" oil is made from, take a look at the MSDS and look for these numbers. (The CAS number for PAO is 68037-01-4).

In brief, don't be so quick to dismiss Rotella T Synthetic as just another "synthetic pretender." It's made with the same base oil as Shell's Helix Ultra, and everytime you see Ferrari win a Formula 1 race, that's the oil in the engine.""

 

[RalphVa]

I use 5w30 Mobil 1 in my diesel tractor and 10w40 Mobil 1 in my diesel 1984 Benz. These are the weight ranges specified in their manuals (Admittedly, the Benz one is probably WAY out of date based on what is available today.). I have trouble finding 10w40 Mobil 1; so, I've used 5w40 (better) at times (when I can get it) and currently have a 50/50 mix of 5w30 and 15w50 to get the 10w40.

Oil viscosity index is determined by viscosity measurements at 40C and 100C. The oil weight (the 2nd number)specified on the can used to be determined by the SSU (Saybolt Seconds Universal) value at 100F or extrapolated to 100F by the viscosity index; however, I think now they just have a range of actual vis that sets it. The lower vis value is determined by viscosities measured at very low temperatures and is a different temperature for 0, 5 and 10W oils. (I don't recall or have the URL for these specs; maybe others can.)

For best protection at startup (where most of the wear occurs), use a multivis with the lowest first value that you can get. If 0w40 or 0w30 synthetics are available and diesel rated, use them. The oil will be less viscous (easier to pump) at startup and will be MORE viscous at operating temperature (on the very hot bearings and cylinder surfaces) than oils with a bigger first number vis. So, if your manual says 10w40, you could probably safely use a 0w30 and get better performance. (You'll have a lot of trouble finding this though. Better luck finding a 5w40 or 0w40.)

Ralph

 

[IH3444]

Thickness of the oil at operating tempertures is not the advantage with synthetics, film strength is, and it's resistance to shear. The connecting rod bearing surface is the maximum load an engine sees, and the synthetic oil's 3 to 4 fold resistance to shear over a conventional oil is where they shine.