diesel oil into petrol car?

[amshaw]

I know this may sound stupid but.......I have a heap of 15/40 Diesel motor oil kicking around our shed that I use in our Disco......

Is there any reason why I cant use it in our '99 Subaru Impreza (non WRX, non Turbo etc)

Castrol state to use there edge or Magnet oils and from memory they are 10/40 and 5/30 or something like that.........

Any help clearing this up please?

[JDNSW]

15/40 may be slightly higher viscosity than recommended for the Subaru, but apart from that there should be no problem - the oil will exceed requirements for the petrol engine.

Quite a number of farms for example use the same engine oil in diesel and petrol engines, and this is invariably a normal diesel oil. (I don't but that is only because the diesel oil is more expensive, and I don't use enough to buy in large enough quantities to make it worthwhile)

John

[LRHybrid100]

diesel oils have more detergent in them - good for cleaning out an old petrol motor.

LRH

[rick130]

above 0* C a 15w-40 and 10w-40 are virtually indistinguishable in terms of viscosity.
Some lower grade diesel oils (earlier than CI-4, especially if not SL dual rated) may poison the cat (as in catalytic converter, not the moggy ;) )
Otherwise, most diesel oils are a better oil than an equivalent petrol engine oil in that the additive package is more robust, and as LRH said, better detergents/dispersants.

[landrovermick]

I was always told this was good for cleaning out the engine - re detergent etc, but not so god for l;ong term use also in old engines may remove the carbon etc that seals the rings and make the engine blow smoke..... just what i have been told.... ask castrol helpline.

[Pedro_The_Swift]

hmm,
in that case--
I have some RX super I might chuck in the Brumby:D

[LandyAndy]

I agree with other,if the motor is HEALTHY its actually better for the motor due to the extra detergents.
If its worn out it will remove the carbons built up in the motor and actually make the motor use/burn more oil.
Andrew

[Utemad]

hmm,
in that case--
I have some RX super I might chuck in the Brumby:D

The guy I bought my V8 D1 off swore by this stuff. Said he used it in the Disco and his WRX. Reckoned that it was good due to the detergents etc as posted previously.

[shorty943]

During my Navy days, an oil we called, OMD113, went into all Internal Combustion Engines. From the big main diesels of subs and patrol boats, to the generators and boat engines of the ships, even into the Admirals Humber Super Snipe and the ships Mini Moke, it was even mixed into super petrol for the rescue boats outboards.

OMD113, Oil Mineral Detergent, the 113 is a Milspec viscosity index, approximately equal to 20\40.

I'd say use it.

[incisor]

diesel oil is fine if you start using it in a newish petrol motor, but it is not something you start doing in a donk with a lot of klms if it has been using normal engine oil and you are unsure of its service history.

the extra detergent will wash out good deposits as well as bad ones if it hasnt had a really good regular service history in my experience.

i always run my petrol motors on diesel oil and have never had a problem that could have been related.

[olbod]

When I had my V8i donk totally rebuilt it was filled with
Penrite HPR Diesel 15. Advised that this was the best.
I checked with Penrite for confirmation and was told
"Yep, use it ".
I have to give it an oil change this weekend, so Diesel 15 going back in !
Cheers.

[Blknight.aus]

During my Navy days, an oil we called, OMD113, went into all Internal Combustion Engines. From the big main diesels of subs and patrol boats, to the generators and boat engines of the ships, even into the Admirals Humber Super Snipe and the ships Mini Moke, it was even mixed into super petrol for the rescue boats outboards.

OMD113, Oil Mineral Detergent, the 113 is a Milspec viscosity index, approximately equal to 20\40.

I'd say use it.

omd 113? dont you mean omd 110 or 115? or are you talking back in the day when the boats had oars and drumsmend?

113 is replaced by 115 now......

[shorty943]

omd 113? dont you mean omd 110 or 115? or are you talking back in the day when the boats had oars and drumsmend?

113 is replaced by 115 now......



OM 100 for steam. No detergent.

OMD 113 for ICE's.

I did get discharged in 1978, so there may have been an upgrade or 2 since then.:D

[amshaw]

Sorry I should have said the Impreza has done 86k.

I have a 20L drum of each the following oil in our shed;
***********************
Castrol FMX 15/40
APi sm/cf
Part#117822.
Label on drums says;
"Synthetic Fortified motor oil recommend for petrol & light Diesel engines"

***************************
Castrol RX Super
SAE 15w/40
APi ci-4
************************
Castrol GTX Diesel
15/40
B3/A3
APi SL/CF
**************************

So I have heaps of oil to play with , but Im thinking it may be an issue if I use it in the Subaru.....So Im happy to hear anymore input ;).

I may even sell the FMX on ebay because I cant even use it in our '06 RA Rodeo.:(

[graceysdad]

In the bad old day when the Valiants were still being made, its was recommended to run Dieso oil in the Hemi 6s to fix a rattly lifter problem that was inherit with the 245 ELB motors, using it in engine with lots of ks is not wise, best to err on the side of safety and dont run it in a Subey

[amshaw]

Thankyou for everybodys input/comments.

I spoke to our local Subaru dealer today and asked what they use.......And was very shocked what he said.

Valvoline XLD 20/50 :eek2:

The dealer/owner/head tech man and gen great bloke said they have always used that, and in 30 odd years never had any probs using it.

He also said the oil spec in the owners manual is for the euro countrys only ie 5/30 or 10/30.......:huh: I thought its abit strange has Subaru oz should have a stick on bit stating that we should use a certain spec oil:confused:

So you can buy that oil anywhere and its bloody cheap, I have bought that brand and type for the later model commodore's Ive had in a previous life.....:angel:

He also said not to use the Diesel oil as it has way to much cleaning power.....I trust him so I will not use it.....But thanks very much to those who had some input anyway ;):)

[rick130]

<snip>

He also said not to use the Diesel oil as it has way to much cleaning power.....I trust him so I will not use it.....But thanks very much to those who had some input anyway ;):)

you're kidding, right ?

most mechanics know eff all about oils and lubricants, only what a rep or salesman tells them. They also often use bulk, cheap oil at dealerships, and it often falls outside recommended oil specs....
There is a big difference between "....having no problems.... " and using something that works a bit better. ;)

way too much cleaning power ? in an engine that's only done 80,000km ? how much crud will have built up in that time with good lubricants and regular servicing ?
check the specs on most diesel oils, they are dual rated for general fleet use. The really good diesel oils are SL/CI-4+ and all the relevant ACEA specs. The API SL petrol engine oil spec has only been superseded by SM in the last twelve months or so, and most diesel oils don't meet it as the additive package is too robust. The new CJ-4 spec will meet the SL spec as it is a very low ash spec, but I don't know of any CJ-4 spec oils yet available in Oz.

[amshaw]

you're kidding, right ?

most mechanics know eff all about oils and lubricants, only what a rep or salesman tells them. They also often use bulk, cheap oil at dealerships, and it often falls outside recommended oil specs....
There is a big difference between "....having no problems.... " and using something that works a bit better. ;)

way too much cleaning power ? in an engine that's only done 80,000km ? how much crud will have built up in that time with good lubricants and regular servicing ?
check the specs on most diesel oils, they are dual rated for general fleet use. The really good diesel oils are SL/CI-4+ and all the relevant ACEA specs. The API SL petrol engine oil spec has only been superseded by SM in the last twelve months or so, and most diesel oils don't meet it as the additive package is too robust. The new CJ-4 spec will meet the SL spec as it is a very low ash spec, but I don't know of any CJ-4 spec oils yet available in Oz.

Ok thanks for that I guess;).......Looks like Im back to square one again :confused::confused:.....nothing is easy is it anymore is it.....All I want to do is put some good oil in the subaru, but use what I have in the shed if I can , but not at the risk of blowing up the motor......:angel:

Owners Manual say to use;

API SJ or SH
CCMC G4 or G5
ACEA A1, A2 or A3

SAE Viscosity No; 30, 40, 10w-50, 20w-40, 20w-50.

Im in the south western part of Vic, gets to about -5 dec to 45 dec out here (min & max temps), so what sould I use?

Happy to hear more :)

I have a 20L drum of each the following oil in our shed;
***********************
Castrol FMX 15/40
APi sm/cf
Part#117822.
Label on drums says;
"Synthetic Fortified motor oil recommend for petrol & light Diesel engines"
***************************
Castrol RX Super
SAE 15w/40
APi ci-4
************************
Castrol GTX Diesel
15/40
B3/A3
APi SL/CF
**************************

[rick130]

Sorry Andrew, just re-read what I wrote and it sounds a touch, err, strong.

Personally I'd use any of those oils in the Suby till the drum is empty and be happy.
GTX Diesel and FMX are dual rated oils and easily exceed the API specs Subaru lay down for your engine (SL and SM respectively) and I personally wouldn't go heavier than an xW-40 in a petrol engine these days, you are just creating more drag without any extra protection.
In the US no one uses anything heavier than an xW-30 in Subies, even in Texas and Arizona where it is at least as hot as here in summer. The Yanks just can't believe we use stuff like 20W-50 and 25W-60 here. It's unheard of over there. These days the factory grades for most Chevs, Fords, Honda's, Mazda's and Toyota's sold in North America is 5W-20 !, has been for a few years now and there is absolutely no evidence of premature engine failures or excessive wear compared to engines in the past running 10W-30, and the Yanks tend to keep vehicles like we do here.

Think of it this way, no one that runs a huge truck uses anything heavier than a 15W-40 in the hottest of summers here as they protect fine, and if the cooling system is doing it's job, the oil doesn't get too hot.

Put it another way, Valvoline make some good oils, their full on diesel oils are developed in conjunction with Cummins, but those three Castrol oils are all much better oils than 20W-50 XLD ;)

[twitchy]

I know this may sound stupid but.......I have a heap of 15/40 Diesel motor oil kicking around our shed that I use in our Disco......

Is there any reason why I cant use it in our '99 Subaru Impreza (non WRX, non Turbo etc)

Castrol state to use there edge or Magnet oils and from memory they are 10/40 and 5/30 or something like that.........

Any help clearing this up please?

YES THERE IS!!!!!!!!!! The high detergent levels in the diesel will peel so much crap out of a used engine it doen't do them any favours, the crap can block oil paths & filters & cause lots of dramas.
If it was a fresh engine there would be no worries with it.

[rick130]

YES THERE IS!!!!!!!!!! The high detergent levels in the diesel will peel so much crap out of a used engine it doen't do them any favours, the crap can block oil paths & filters & cause lots of dramas.
If it was a fresh engine there would be no worries with it.


how much sludge and carbon buildup is there going to be on a vehicle with 80,000km and regularly serviced ?
The detergent levels in diesel oil isn't that high, otherwise Japanese indirect injected diesels wouldn't have the problems they do with sludging. Talking to oil blenders, there is only so much 'room' inside an oil for additives, and the really good diesel oils are approx. 25% add pack, but this includes all the EP and anti-wear additives, as well as the detergent/dispersents, but the levels aren't that great that huge chunks of carbon are going to be ripped off oil galleries in an instant.

The worst that can happen is that with long term use the cat may be 'poisoned' by the metallic ash additives (phosphorous ?) used in diesel oils.