The good oil...?

blacklabel · 09-08-2007, 05:46 PM

Gidday all,

Wasn't sure whether this should be in "general tech" or not,so here goes.
I'm giving my 98 AU Futura (255,000km,quiet and smooth) the big birthday service on the weekend.Oil,filters,coolant,plugs etc....
Now I know they use 5-30 oil,and is recommended in the manual.

My question is- would a 15w-40 grade oil be ok,and has/is anyone using this grade in their AU?

Why am I asking? Because I have a brand new 5lt pack of CastrolGTX 15w-40 in my garage, and the guy at Supercheap reckoned it would be sweet for my age/mileage and engine.(but he was wearing a HDT jacket...

: )

Thanks.

Casper · 09-08-2007, 05:52 PM

With that sort of mileage a 15-40 would be better than a 5-30 oil. Go ahead and use it.

The Monty · 09-08-2007, 06:11 PM

I was using 15W40 all the time, GTX3, but I dropped to 10W30, also GTX3, as I found the cold starts in winter, it took a while to build a lot of pressure.
Both seem to work fine for me, and Im at 213000.

blacklabel · 09-08-2007, 06:34 PM

Thanks for tips! I will go ahead and use it.
Will be interested to see whether there will be any noticeable differences in performance,consumption,temp etc...over the next few thousand km's.

matt9889 · 09-08-2007, 08:43 PM

i might be wrong but the difference would be fuel economy vs. engine protection. the 10w30 supposed to be better on fuel but thicker oil( 15w40) coats parts better. penzoil are supposed to make a good 10w30

nob92@ · 09-08-2007, 10:57 PM

i used 10w 50 in mygirl gets good pressure and engine seems to run better.

**Mechan1k** · 09-08-2007, 11:12 PM

I use 15W40 all the time ... i do a lot of kays ... and i replace it regularly.
The key is to not leave a long time between oil changes ... oil is really cheap insurance for your engine ... I like to change it often.

**Stav** · 09-08-2007, 11:15 PM

Go penzoil street gt oil. If it was any better you would use it for frying.i think its 20 50 or 10 50.I have the sticker on my garage wall.

sly · 09-08-2007, 11:57 PM

Quote:

Originally Posted by blacklabel

My question is- would a 15w-40 grade oil be ok,and has/is anyone using this grade in their AU?

Why am I asking? Because I have a brand new 5lt pack of CastrolGTX 15w-40 in my garage, and the guy at Supercheap reckoned it would be sweet for my age/mileage and engine.(but he was wearing a HDT jacket...

: )

Thanks.

I let a salesman talk me into 15W40 oil at around 220,000km and noticed the performance was noticebly sluggish under 3000rpm. Went back to 5W30 and it picked up again. At 315,000km it uses maybe half a litre (of 5W30 semi-synth) every 10,000km. Some brand new cars use more.

If your engine is worn, compression is down and oil consumption is up then a heavier oil would be worthwhile.

**Stav** · 10-08-2007, 06:34 PM

After going from the penzoil to mobil oil for the past 1000 kays I refilled with penzoil today.There was alot of metal flakes in my oil.At the track with the penzoil my car ran quiet as a mouse even driving home.With the mobil oil my car started to rattle at the end of the night like the lifters were damaged.On my way home I thought I had blown something up.Sounded like the regrind cam I had in there from the past.I will never reccomend mobil oils or ever put them in my car. Just topped up with penzoil again and its seems nice and quiet.Hope there wasn't terminal damage from the other oil. If you want to find a good oil the best test I have found is simply pull the dipstick out and feel the film between your fingers.If you can feel the friction of the opposite finger then your oil sux or is very old.

blacklabel · 11-08-2007, 11:21 AM

Quote:

Originally Posted by Stav

After going from the penzoil to mobil oil for the past 1000 kays I refilled with penzoil today.There was alot of metal flakes in my oil.At the track with the penzoil my car ran quiet as a mouse even driving home.With the mobil oil my car started to rattle at the end of the night like the lifters were damaged.On my way home I thought I had blown something up.Sounded like the regrind cam I had in there from the past.I will never reccomend mobil oils or ever put them in my car. Just topped up with penzoil again and its seems nice and quiet.Hope there wasn't terminal damage from the other oil. If you want to find a good oil the best test I have found is simply pull the dipstick out and feel the film between your fingers.If you can feel the friction of the opposite finger then your oil sux or is very old.

Yep, I will be keeping an eye on things for a few km's to see how the heavier grade goes.Might not actually happen this weekend though,as my damn sump nut won't budge...

:

VCT_XR6_UTE · 22-08-2007, 08:03 PM

hey, i baught mobil 5w50 fully synthetic for my au xr6, havent put it in yet, but was wondering if it will be ok to use?

b2tf · 22-08-2007, 08:12 PM

Quote:

Originally Posted by VCT_XR6_UTE

hey, i baught mobil 5w50 fully synthetic for my au xr6, havent put it in yet, but was wondering if it will be ok to use?

Seems a bit thin to me but I believe a few on here use it and have no problems.

Personally I use 15w40 and change every 5000, but thats in an XR8.

SVR73 · 25-08-2007, 12:52 PM

Fuchs Super GTO, Redline 10W40 and Motul have served my VCT better than any other brands I've bought so far and I've tested alot with the forte

irext · 08-09-2007, 09:17 PM

I've always used Magnatec 10W40 since the car was almost new. It's now done 250000kms uses no oil and sounds just the same as it did at 50000kms.