Very quick question guys, I was having my 1997 sti v3 driven 500 miles up road to me and wanted to have an oil change. Garage said they used shell fully synthetic 5w-30(even though I told them to use millers). Reading up the 10w-40 is ideally suited to the ej20. Should the 5w-30 oil be ok for 6 months or would you recommend changing as a priority?

Thbks jn advsnce

 

5-30 is what Subaru recommend, so they are following manufacturers specs. Both are fine in normal use

 

Thanking you

 

At least 10w/40 if it were me

 

I would not put 5w30 in a v3 Impreza.
As said 10w40 or 10w50.

 

Is this what Subaru recommend in a Classic v3sti jdm car?
Or what Subaru recommend in a newage ej207 UK car?

 

in general terms use a min of 10w in a GC8 car and new-age cars can use 5w grade dependant on exact use but personally would use 5w40 rather than 5w30...........

as Ossett above states general use for classics is a 10w40 grade

 

As already said really

My rule of thumb is

Old engine that's been modded with 100k plus on has a 10/50 oil to help those worn big ends

Original unmodded engine has 10/40

 

Thanks all - appreciate that

 

@ asperformance- in a car that has done 90k, is a sti v3 and is modified to run 315 bhp. What is the ideal oil to be safe? Thank you

 

I would tend to agree with the previous comments. If it were my car i'd run good quality 10w40 in an engine that has the stock bearings still fitted and anywhere near or over 100k on the clock, and 10w50 if it's had race bearings (acl, kings etc) fitted.

From my understanding the stock bearing clearences when new are small so they can use 5w30 to reduce friction (better emissions). But at higher mileage they would have worn a bit.

Race bearings tend to run larger clearences so need a thicker oil from the off.

 

Ok great I'll order a quality 10w- 40 then thanks

 

10-40 or 10-50 then folks based on the car and profile?

Thabk you

 

Just to add (from info gleaned from Opie)...

I'd be inclined to use a full ester, fully synth 10W-50 for your spec.

I use Fuchs Titan Race Pro S 10w-50 in my MY1999 STi, running 384/349... Have been for nearly 7yrs now.

Millers CFS and Motul 300V equally good.

These are all top-notch oils - see posts on this page:

https://www.pistonheads.com/gassing/...&t=237642&i=60

 

THabk you!!

Is there any downside in going for a 10-50 over a 10-40?

 

Yep about a fiver

 

- Thicker oil means more 'drag', so can result in some (negligible) power loss.


- However, as mentioned, the important bit is: in higher milage cars with more worn big-end bearings (and/or aftermarket bearings with greater tolerances), the extra thickness is designed to 'take up the slack' so to speak i.e. keep the pressure integrity 'twixt the main and b/e bearings. This is especially important when the oil thins out in a hot engine when at high rpms (especially on F.I. cars), and therefore when its more prone to any knocking which may occur.

 

One last question!

Millers cfs nanondrive or cfs conpetitin for fast road use and the very odd track day?

 

That nano drive CFS is nearly £70

I've always used millers 10-50 cfs never had an issue from cold to hot

 

Yeah ain't cheap but wonder if it is worth the extra for normal fast road use - prob not. Hoping someone can clerify. It sounds like 10-50 is the way forward regardless thanks again

 

Technically - on paper at least lol - Nanodrive is one of, if not the most advanced formulation out there.

But not many members on here seem to use it...(?)

 

£53.95 from opie with 10% discount code

 

I've been using Total Quartz RACING 10W50 Fully Synthetic Engine Oil.
10ltrs for £51.50

 

I pay £30 for 5ltrs of millers cfs 10/50

 

Where from??!

 

I get a free screen wash tab with my Total Quartz

Where you getting your millers cfs from?

 

I have good Friend called Ollie who owns a local Motorsport garage "Phoenix Motorsport" he works on them lotus Elise thingies and other fancy track cars he's a millers distributor aswell its where I get it from for the past 8 years
He looks after me really well


He also does all my alignment side of things if needed aswell

 

I have ordered the 10w-50 of the millers cfs nt•. Wondering if I have made the wrong choice though as it states for rally or race cars. Are any oil experts about to advise lenif it should be ok in my1997 v3 Jen sti?

Tha k you!!

 

It is a rally car
I use 10w50 as do many others.
You would of been fine with 10w40
I choose 50 as its a highish mileage and highish power v3sti.

Ps I'm no oil expert lol

 

Ha ha ok sounds like it should be compatible and will not cause more harm than it prevents lol . Thanks. Hopefully an oil expert comes along and hugs me to say everything will be fine son lol