Ok To Go With 10W40 Oil In My Diesel Yaris?

[Tommygunn]

Would I be ok to fill my 2002 Yaris D-4D(Diesel) with 10W40 oil as opposed to the usual 10W30?
If it helps the car has about 93,000 miles on the clock and we're approaching an Italian winter that could, at the extreme, be knocking on -5°C.

Reason I ask, is that I can get a deal on a load of the stuff and I can also do my Fiat at the same time.

Cheers,
Tom.

[Cyker]

I don't have my handbook handy (haha) but I think 10w40 is listed as an acceptable oil for the earlier D4Ds.

As it is thicker it might impact the mpg a bit tho'.

I normally use 5W40 so 10W40 should be okay too, but I did find 10W30 made the car sound a bit rougher when fired up in the cold winter mornings so you may get a similar effect. Was fine once it heated up tho'.

Edit: According to Opie Oils, 10W40 is the correct oil!

http://www.opieoils.co.uk/products-for-my-vehicle.aspx?product=Car-products&make=TOYOTA&model=Yaris%201.4%20D4D&modelyear=2002%20onwards#resultsB

For some reason I was thinking it was 5W30 but that's the newer Yarisususues I guess!?

[Tommygunn]

Thanks for the info. For the vast majority of the time the car is park underground, under the house, so cold starts in the morning are not really an issue per se.

A useful link you posted to there.

I also noticed that below the standard oils, for the Yaris, that the upgrade oils are all 5W-40. Surely, you'd just have a super duper version of 10W-40 or is 5W-40, overall, just more refined, more expensive to make and better for the engine?

Tom.

[Parts-King]

Instead of worrying about the grade, you need the right spec, you could have 10w-30 of the completely wrong specification

http://www.toyotaownersclub.com/forums/topic/148359-engine-oil/

Kingo

[Tommygunn]

Parts-King,

That hasn't really clarified anything for me. Can you explain further?

Tom.

[Parts-King]

5w 30 10w 40 20w 50 are just grades, th viscosity of the oil, it tells you nothing of its specification

The correct specification for your car is 5w 30 API SL ACEA A1/B1

You can buy oil with the right viscosity but the wrong spec

Once you have found the right spec (or better) then choose a decent known brand

Kingo

[Cyker]

The numbers are just viscosity grades - 30 is thinner than 40 etc. The number before the W is the viscosity rating at cold temps.

My experimenting with the 5W40 was just to help improve cold starts in the winter, the reasoning being that 5W40 should flow better in cold temps than 10W40; It does seem a bit easier to start the engine on freezing days!

It's also fully synth vs. the semi-synth 10W40 so should hopefully degrade slower and have a better capacity to soak up acids and soot and other crap from the combustion...

As Kingo says, the oil spec is important too, but most oils in that viscosity band should have the right spec. Still, worth double-checking before you plonk down the money!

@Kingo - Are you sure the 5w30 API SL ACEA A1/B1 is for the Mk1 D4D as well? I know it's the standard spec for the Mk2 and Mk3 D4Ds as they need thinner oils to get good MPG, but my manual says recommended grades are API CF-4, CF, CE or CD, with recommended viscosities being 5W30, 10W30, 15W40 or 20W50 (!!).

I've been buying stuff rated for API CF or CF-4...

[Madasafish]

I have been using 5-30 fully synthetic to either spec as above for the past 5 years with no issues.