[XinZhao]

It says that 0w-30 for diesel is to be used only where temperatures rarely go above 10 °C
And for 5W-30 it can be used up to 40°C ambient temperature.
It does not make sense to me as  the number 3o is the working temperature (100C) viscosity - and is the same.

Can somebody check their book? I guess its about some kind of a mistake. I already bought 0W-30 Acea c3.

[CraigB]

A good branded 0W-30 oil can still be used in ambient temperatures up to 50C though -40 would cope easier at the higher temperatures.

0W and 5W relates to oil thickness at start up, going by your locality a 0W-30 would be the preferred viscosity.

[XinZhao]

Here is the table from the book/user manual

How do you explain this then?

[CraigB]

What oil have you bought? if it's suitable for both petrol and diesel then you'll be fine, if your not comfortable using it then return it and get another.

[XinZhao]

I want an explanation of why hyundai sais about diesel oil 0w-30 is only for extreme cold area, (from the table: up to 10°C)

I bought shell helix ultra ect 0w-30 c2/c3 ACEA C3 (because I have DPF)

Does it mean that 0W can br too thin? - regarding cold start.

I just can't understand this!

[CraigB]

I think you'll be right with what you've bought (depending on your exact ambient tempuratures ), that oil is suitable also for petrol so it has a larger coverage range than what is recognised in the manual for diesel alone.

For cold start in cooler climates the 0W is beneficial as it'll circulate through the engine quicker but if you're really concerned about it then ask your local Hyundai service centre for advice or see if you can return it and get Shell Helix Ultra ECT C3 5W-30

[XinZhao]

The only reason I can see is that it might ve too thin in a way that it drains* much mire before cold starting in the morning.

*If the temperatures are about 35 when turning the engine off and invthe morning about 25°C

In the service where I live, they don't know shit. Pardone me for my language but I tried asking some questions before and they don't know answers and they misinform you.

[Phil №❶]

I'd buy the 5W-30 stuff. Your car will still start and warm up with the added protection of being able to fully utilise the vehicle.

[CraigB]

If the temperatures are about 35 when turning the engine off and invthe morning about 25°C

Your temps are warmer than I was thinking, as Phil has mentioned...buy the 5W-30 stuff

[XinZhao]

Those are extremes, we had it last summer for several days (even higher temps).
Anyway I'll use the 0w-30 in the Autumn - This oil is new on the market and costed 40% more then the 5w-30.

Practical reasons on the side, but my mind just hopes this eould be explained someday. Because, this table basically shows that is better to use 5w-30 then 0w-40.
However, there is no difference in the max ambient temperature of 10W-30 im comparison with 5w-30, which is odd.

This table is from the book of FD model. Can anyone check the table of the GD?

[Phil №❶]

However, there is no difference in the max ambient temperature of 10W-30 im comparison with 5w-30, which is odd.

The 30 figure denotes the oil's high temp performance limitations. As they are the same, why is it "odd"

[XinZhao]

Sorry, i meant to say it's "odd" because they aren't consistent.

I can't understand how oil can be too thin in cold start denotation.
I just think this is some kind of misstype, they probably meant 0W-20..

[The Gonz]

Useful chart. If I read that right, for Adelaide I can save my money and go 20W-50!

[baroudeur]

Sorry, i meant to say it's "odd" because they aren't consistent.

I can't understand how oil can be too thin in cold start denotation.
I just think this is some kind of misstype, they probably meant 0W-20..

A very complicated subject so don't get too involved trying t understand it.

This may help ....or not!    http://tinyurl.com/jgzw4nj

0W is extremely thin and, generally, to be avoided unless conditions comply with the manufacturer's specified temperature range.

If your winters drop to a regular -30°C and summers never get above 10°C then  0W-30 will be fine.

If, on the other hand, winters are generally above -22°C and summers always below 40°C the 5W-30 oil will be suitable.

In an extreme case of -30°C winters and 40°C summers  you will need to change oil in spring and autumn to suit and there are parts of the world where this is necessary.

In your case I suspect 5W-30 will be the correct grade..

[AlanHo]

2013 GD UK manual