JASO DH-1 or DH-2 in a Toyota 1HD-FT

[blue.cruiser]

I have a 1996 Land Cruiser (HDJ81) with the 24v 1HD-FT engine. I live in Japan, so the oil available is JASO spec. I do have access to some American brands on base, but the selection isn't great.

There are two main diesel oils specifications for truck engines:

• JASO DH-1: A high sulphated ash oil designed for the lubrication of Heavy Duty Diesel Engines, not suitable for exhaust after treatment devices.
• JASO DH-2: A low sulphated ash oil designed for the lubrication of Heavy Duty Diesel Engines, particularly when equipped with exhaust after treatment devices.

JASO DH-1 and DH-2 oils seem to differ in the sulphate ash. The JASO specifications manual goes on to say that you can use DH-2 in a car that predates SCR and DPF devices, but not the other way around as it will clog them. I have to imagine that if there were no benefit of the high sulphates ash oil (DH-1) then they wouldn't go through the trouble of selling it, right? So what do you get out of the DH-1 spec that you're "giving up" so as to not clog your emission control devices?

What oil would you run in one of these old mechanical Toyota diesel engines that predate the ultra low sulfur diesel oil and fuel?

Ok, now what if I told you my cruiser does have an A'PEX CATA aftermarket catalyst which seems to have been fitted because of the Tokyo retrofit program. But it's not a regenerating DPF or a SCR that uses DEF. It really just looks like a gasoline car catalyst. Would this thing get messed up from using DH-1 oil? I don't suspect that it really does a whole lot as it's been mounted all the way at the end of the exhaust pipe and probably doesn't get that hot. Maybe I should just cut it off anyways as Okinawa doesn't care about diesel exhaust.

 

[MSCH]

I'm assuming you mean it has a aftermarket diesel oxidation catalyst.. which have been around for years.
either oil will work fine..

 

[Fabulous50s]

I asked the same thing about my diesel tractor that doesn't have any emissions equipment.... and crickets.

 

[MSCH]

I asked the same thing about my diesel tractor that doesn't have any emissions equipment.... and crickets.

honestly, any older diesel engine oil specifications have been significantly superceded by multiple oil classification changes in the intervening time period.
For instance I think the HDEO's common in the USA in the 90's were classified as CE or CF.. whereas the current classification is CK4.

same applies here. the oils you are looking at are borderline obsolete, so you can just rest assured that anything with a newer classification rating outperforms what was available in the 90's.

 

[Fabulous50s]

I guess the question is what (if anything) is really left on the table due to the low ash mandate to save the exhaust aftertreatment.

Same for lower ZDDP.

 

[MSCH]

I guess the question is what (if anything) is really left on the table due to the low ash mandate to save the exhaust aftertreatment.

Same for lower ZDDP.

the modern Ck4(2017) and preceding CJ5(2007) are the two in place right now. There is also FA4 which is a bit newer and revolves around the new lower viscosity oils getting specced in some of the newest most modern diesels.

 

[blue.cruiser]

Alright, found something credible.

source: https://www.jalos.or.jp/onfile/pdf/2009_DEO_Seminar.pdf

The DH-1 oil has nearly twice the base number as the DH-2 oil. A little higher lead allowed in DH-1 standard. Soot dispersancy standards are the same. (click the link for all the data. It's at the end of the PDF). So in theory you could have longer oil change intervals with the DH-1 and all it's sulfury goodness.