Some basic Questions about cultus

[zainbintariq248]

I bought a used cultus and trying to take care of it as it's my first car.
I tried online to find the PDF manual of this car because there are some questions that i think suzuki should be genius enough to answer in the car manual but i didn't find any manual or relevant document of suzuki cultus,Its like cultus didn't even exist in international suzuki forums etc
here are some question and it will be very nice of you to check your manual (if you still have it) and then answer me!
1-Recommended Engine oil type ?
2-Recommended Oil change period ?
3-Recommended Refrigerant type in compressor and Refrigerant Oil type (number etc)?
4-What is the genuine compressor that comes with cultus EFI?
5-When should owner change the air filter of cultus ?
6-Gear oil change time period ?
6-When should fuel injector should be serviced or replaced ?

Thank you in advance for answering my questions i appreciate that !

[hassantahir2]

1- Any good 10W-40 API-SG, SJ will work.
2- 5000 km along with oil filter.
3- R134a is recommended in Cultus and ND-8 OR SP-10 oil is used from factory according to the system installed in car.
4- Cultus used to come with Denso as well as Sanden unit's from factory so part number's for both compressors are different. BTW Denso one is 10P08E don't know about Sanden.
5- Under dusty conditions 5000-6000km.
6- 40,000 km use any good API-GL4 SAE 75W-85 OR SAE 90 Oil.
7- Don't know...

[zainbintariq248]

why 10w-40 isnt 20w-50 good ? what's the difference ?

[hassantahir2]

These number's represent the viscosity of oil.
The number written with W represents the cold flowing ability/ viscosity of oil and the other number represents the viscosity of oil at operating temperature.
In other word's 20W-50 would be more thick at cold temperature and also more thick at operating temperature. 10W-40 would be a bit less thick than 20W-50 at both cold and operating temperature.
If the engine is healthy and not reducing oil then one should stick to the manufacturer recommended oil for Cultus i.e. 10W-40.

[nfsmostwanted]

Beautifully explained