I'm having some issues with a vehicle using Mobil Delvac 1, 5-W-40 Fully Synthetic Oil, in a turbo diesel Toyota landcruiser 4x4 converted to run LPG in conjunction with the diesel at the same time.
Heres the content today of my email to exxonmobil. Lets see what the experts have to say!
Quote:
Dear Sirs,
Could you please have one of your expert oils engineers/chemists advise me in writing - which is the best / correct Mobil oil to use in my vehicle?.
I have used your online web resources to try and ascertain this but been unsuccessful at finding the answer I seek.
1. My Vehicle is a 1992 manufactured Toyota Landcruiser 4x4 Turbo Diesel Station Wagon, with the IHD-T Factory turbo engine.
2. The vehicle is Non Standard, in that it has been modified by Australian Firm Diesel Gas Australia http://www.dieselgasaustralia.com.au/ to burn LPG at the same time as the normal diesel fuel.
3. I have been running Mobil Delvac 1 fully synthetic oil for at least 20,000 km's now, and getting the used oil analyzed by two independent laboratories now (Westrac Equipment in Perth Western Australia & Oilgaurd in the USA).
4. Your web based selection tool at http://www.datateck.com.au/lube/mobil_au/ recommends
MOBIL SUPER DIESEL 15W-40 or MOBIL DELVAC SUPER 1400 15W-40 or MOBIL DELVAC MX 15W-40 or MOBIL SUPER XHP 15W-40
It doesn't mention Mobil Delvac 1 5W40 Fully Synthetic Oil, which we have been using because we were advised at a US Based web forum that it was the best oil available anywhere in the world for this vehicle (Forum is BITOG = Bob Is The Oil Guy http://www.bitog.com).
5. Your Web Based Mobil Product Guide http://www.mobil.com/Australia-English/LCW/Files/2006_Mobil_product_guide.pdf, doesn't mention the oils that your web based selection tool recommends for the vehicle (Nor Delvac 1 Fully Synthetic 5W40).
The last two used oil analysis records for this vehicle by Westrac Equipment (attached) have shown wonderful results for low wear metals etc - however they BOTH mention elevated oxidisation and nitrate levels, suggesting that the vehicle is NOT operating within it's correct operating temperature range! Both samples were taken in our winter during cool weather and the vehicle temperature gauge never registered any high temps - it barely crept above cold.
Can you please advise if we should continue to use Delvac 1 5 W 40 fully synthetic oil in this vehicle? Its a VERY expensive oil to buy here at$20.00/litre - and due to the high oxidation levels we are not able to get extended oil change intervals out of the oil that we had hoped for. We don't believe the engine to be operating outside it's normal temperature levels, so are at a loss to explain the high oxidisation and nitrate levels being experienced.
Whether these are in some way attributable to hight EGT's (Exhaust Gas Temperatures) as a result of the LPG conversion - we are at a loss to say.
We also don't know if there is a more appropriate Mobil oil to be using for such a converted engine running both diesel and LPG at the same time.
I look forward to any advice you can provide us in this respect as to just which oil we should be using in this vehicle, given that Mobil Delvac 1 at this stage doesn't appear to be the correct one, if the used oil analysis results are anything to go bye.
Thank you very much in advance for an advice you can give.
Yours Sincerely
These are the 2 UOA's to which I refer.
Both found elevated Oxidisation and nitrate levels and question the correct operating temperature range of the engine.
So what is the right oil for this vehicle? - everyone on this website seems to suggest Delvac 1 synthetic 5-W-40 is the bees knees for every engine, but in this engine at least - while the wear metals levels are very low - theres no way we can get extended oil change intervals, if the oil oxidises and has elevated nitrate levels at 5000 km change time.
Why doesn't Mobile recommend Delvac 1 on their online selection link for that model and make?
Why don't they have the details of the oil their link recommends in their online selection facility at their oil details link? (Or Delvac 1 for that matter?).
It might be interesting to hear back what Mobil themselves have to say on all this!
The more I have to do with oil, oil analysis and so on, the more I begin to wonder if the whole oil lubrication game isn't some giant [censored] shoot run by crooks!
Cheers
Heres the content today of my email to exxonmobil. Lets see what the experts have to say!
Quote:
Dear Sirs,
Could you please have one of your expert oils engineers/chemists advise me in writing - which is the best / correct Mobil oil to use in my vehicle?.
I have used your online web resources to try and ascertain this but been unsuccessful at finding the answer I seek.
1. My Vehicle is a 1992 manufactured Toyota Landcruiser 4x4 Turbo Diesel Station Wagon, with the IHD-T Factory turbo engine.
2. The vehicle is Non Standard, in that it has been modified by Australian Firm Diesel Gas Australia http://www.dieselgasaustralia.com.au/ to burn LPG at the same time as the normal diesel fuel.
3. I have been running Mobil Delvac 1 fully synthetic oil for at least 20,000 km's now, and getting the used oil analyzed by two independent laboratories now (Westrac Equipment in Perth Western Australia & Oilgaurd in the USA).
4. Your web based selection tool at http://www.datateck.com.au/lube/mobil_au/ recommends
MOBIL SUPER DIESEL 15W-40 or MOBIL DELVAC SUPER 1400 15W-40 or MOBIL DELVAC MX 15W-40 or MOBIL SUPER XHP 15W-40
It doesn't mention Mobil Delvac 1 5W40 Fully Synthetic Oil, which we have been using because we were advised at a US Based web forum that it was the best oil available anywhere in the world for this vehicle (Forum is BITOG = Bob Is The Oil Guy http://www.bitog.com).
5. Your Web Based Mobil Product Guide http://www.mobil.com/Australia-English/LCW/Files/2006_Mobil_product_guide.pdf, doesn't mention the oils that your web based selection tool recommends for the vehicle (Nor Delvac 1 Fully Synthetic 5W40).
The last two used oil analysis records for this vehicle by Westrac Equipment (attached) have shown wonderful results for low wear metals etc - however they BOTH mention elevated oxidisation and nitrate levels, suggesting that the vehicle is NOT operating within it's correct operating temperature range! Both samples were taken in our winter during cool weather and the vehicle temperature gauge never registered any high temps - it barely crept above cold.
Can you please advise if we should continue to use Delvac 1 5 W 40 fully synthetic oil in this vehicle? Its a VERY expensive oil to buy here at$20.00/litre - and due to the high oxidation levels we are not able to get extended oil change intervals out of the oil that we had hoped for. We don't believe the engine to be operating outside it's normal temperature levels, so are at a loss to explain the high oxidisation and nitrate levels being experienced.
Whether these are in some way attributable to hight EGT's (Exhaust Gas Temperatures) as a result of the LPG conversion - we are at a loss to say.
We also don't know if there is a more appropriate Mobil oil to be using for such a converted engine running both diesel and LPG at the same time.
I look forward to any advice you can provide us in this respect as to just which oil we should be using in this vehicle, given that Mobil Delvac 1 at this stage doesn't appear to be the correct one, if the used oil analysis results are anything to go bye.
Thank you very much in advance for an advice you can give.
Yours Sincerely
These are the 2 UOA's to which I refer.
Both found elevated Oxidisation and nitrate levels and question the correct operating temperature range of the engine.
So what is the right oil for this vehicle? - everyone on this website seems to suggest Delvac 1 synthetic 5-W-40 is the bees knees for every engine, but in this engine at least - while the wear metals levels are very low - theres no way we can get extended oil change intervals, if the oil oxidises and has elevated nitrate levels at 5000 km change time.
Why doesn't Mobile recommend Delvac 1 on their online selection link for that model and make?
Why don't they have the details of the oil their link recommends in their online selection facility at their oil details link? (Or Delvac 1 for that matter?).
It might be interesting to hear back what Mobil themselves have to say on all this!
The more I have to do with oil, oil analysis and so on, the more I begin to wonder if the whole oil lubrication game isn't some giant [censored] shoot run by crooks!
Cheers