@ ALI TEPU
Recomended oil for Suzuki Swift is 10w-40 as per Suzuki owner's manual and we should stick to recomended values given by manufacturer and Zic's representative also asked to use oil recomended by manufacturer.
PRE REQISITE
Three types of oils are available in market
"Mineral Oils" which are GOOD. (Price = Low)
"Semi Synthetic Oils" which are BETTER. They are mixture of Mineral oil and Fully Synthetic. (Price = High)
Some manufacturers write "Synthetic Tecnology", "Synthetic Oil" on packing of Oil. These are actually Semi sythetics. Do not think that they are fully synthetic.
"Fully Synthetic" or "100% Synthetic" oils are BEST. Their base oil does not contains mineral oil and they are manufactured in Laboratory. (Price = Highest)
Different Gradings are also available in market like 10w-40, 5w-30, 5w-50, 20w-50 and so on.
We should always use grading recomended by manufacturer and should choose "Mineral oil", "Semi synthetic" or "Fully Synthetic" of recomended gradings after looking at our Pocket.
NOW WE ARE GOING TO DISCUSS YOUR PROBLEM
You have put ZIC A+ (5w-30) and you were previously using Shell Helix (May be HX7) (10w-40)
ZIC A+ is fully synthetic and Shell Helix HX7 is semi synthetic.
Grading of ZIC A+ is slight deviation from manufacturers recomendation and Grading of Shell HX7 is according to recomendation.
If you are in search of best oil, you should use FULLY SYNTHETIC OIL WITH IN RECOMENDED GRADING.
NOW WHAT SHOULD YOU DO?
Don't be afraid and enjoy driving your car without any tension in mind.
If we use 20w-50 oil in a car whose recomended oil is 5w-20 doing large deviation from recomended oil grading we will feel any difference in engine performance after 80k or 90k kilometers.
And you have deviated very slightly in oil grading so there will be no issue.
But remember to put manufacturers recomended grade oil (10w-40) or nearest (5w-40), (15w-40) in next oil change and use fully synthetic oil for best results.
USE GOOGLE TO FIND BEST OIL FOR YOUR CAR.
