View Full Version : The right engine oil?
03-22-2009, 02:02 AM
I recently bought a used mini excavator that has a small 3 cylinder Isuzu engine. The lubrication chart says to use 10W 30 oil. Could this be right? I'm used to putting 15-40 diesel oil in diesel engines but I'm not familiar with these small diesels. I think I'm going to stay with 15-40 anyways? Maybe they just don't have 15-40 diesel oil in Japan.
03-22-2009, 05:12 PM
If the manufacturer's chart says use 10W30, you should use 10W30. The do a lot of testing for this sort of thing...
03-23-2009, 10:33 PM
OK, I got some shell Rotella T 10W30 diesel oil from Walmart. My engine specifies an API CD. The rotella meets API CJ-4, CI-4, CH-4, CG-4, CF-4, CF/SM, SL, and SJ. Do these meet the CD requirement? Or am I getting too carried away with this.
Also my drive motors call for SAE 90 wt oil. I bought 80W90. Will the 80W90 work or is 90 wt completely different?
03-24-2009, 12:11 AM
The API CD is an heavy duty diesel oil spec that was introduced in 1955 according to the bulletin I downloaded from the API web site. The file size was to large to upload as an attachment. If you want to visit the site and read the bulletin here's the link: http://www.api.org/certifications/engineoil/categories/upload/English_Oil_Guide.pdf
If the Shell oil you purchased meets any of the CI-4 specs you are good. I to would recommend sticking with a 10W-30 as the OEM has clearances that in cold weather lubrication on start up might be compromised by the heavier viscosity oil. On an oil analysis you are allowed one viscosity grade increase or decrease to stay in spec. Would 15W-40 ruin the engine immediately, no. Would fuel economy suffer with 15W-40, yes. Would cold start up lubrication be compramised to some areas of the engine, possibly.
On your drive motors, what spec oil does the manual call for (GL-4, GL-5 or something different)? A GL-5 contains extreme pressure additives, which most are a sulfur base. The GL-5 fluids will attack yellow metals such as brass, bronze and copper. If your drive motors don't have any yellow metals, then most likely a GL-5 80W-90 gear oil will perform without any problems. The 80W-90 simply is a multi-viscosity gear oil that has cold flow characteristics of a 80W; and at operating temperature has flow characteristics of a 90W. Multi-viscosity fluids are beneficial in colder climates where cold flow is an issue. If you are in a warm climate and cold flow is not an issue, then you can probably save a little money by purchasing a quality straight weight gear oil. You don't need to spend the extra money for VI improvers.
Send me the drive motor OEM spec and I'll cross it if necessary. Thanks for submitting these questions to the forum.
03-24-2009, 12:21 AM
One more thing, comfort food for thought here. I alway recommend a AMSOIL HDD 5W-30 synthetic to all my customers. I currently have the 5W-30 in small Perkins and Kubota engines both air-cooled and liquid-cooled; light, medium and heavy duty trucks and off-road construction equipment. Here in NE Iowa we run the 5W-30 year round. All engines have perform flawlessly and the oil sample results are better than conventional 15W-40.
I know I grew up on a diet of 40W fluids, and then when 30W started being the factory fill on everything I was stumped. Now we have 20W oils as the OEM recommended viscosity for gasoline engines; and the Europeans are testing 20W synthetics with great success in the over-the-road truck diesel engines. It will be here in the USA before you know it.
03-24-2009, 12:31 AM
Wow, thanks for that information. I'm getting all the oil specs from the lubrication chart which is stuck to the window of the cab. I wrote down the spec for the drive motors which said (GL-4 GL-5, SAE 90). The oil I bought for the drive motors is Shell Rotella heavy duty gear oil 80W90 which meets the GL-5 spec according to the back of the bottle. Where I'm at in California the temp can get to 110 deg. in July - Sept and can dip to the 20's (overnight) Dec - March but is usually in the 60's - 80's the rest of the year.
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