Hey guys, I recently changed my engine oil with Shell Helix HX7 and I felt the engine and driving experience is not so smooth compare to Castrol that I used previously. Anyone recommendation for good engine oil for my car? Driving Corolla AE with 300k mileages.

Define "not-so-smooth" experience. Also what was the Castrol's viscosity, 5W30, 10W40?

petronas all the way

I use Semi-S Shell , so far best i use , but i did engine flushing everytime i service lah

when use the current shell helix hx7, the engine started to vibrate after few hundreds of km only. the castrol i previously used is castrol magnatec 10w-40. if i use slightly pricy engine oil for my old car can? scare problem will arise

mind elaborate more about engine flushing? did you do this yourself or let the shop do?? sry I'm new to these stuff

Double post

This post has been edited by jeushyun: Sep 26 2019, 09:49 PM

which model?

I dunno why u wanna change brand. If that brand works, keep using it. It is a machine. You do not need to give it new oil flavours.

machine have feelings too....

you want the best? Go for Ester based engine oils - Motul, Amsoil, Royal Purple etc.

Where or who did you buy that HX7 from? Can you trust the source of this HX7?

And don't be too adventurous to flush your engine at 300k km. Chances are you will make something worse. Better think thru b4 committing.

AMSOIL isn't ester based though

No idea on royal purple

I actually got the HX7 from shell petrol station directly..

Go online and find out both oil kinematics. Look at the 40°C & 100°C viscosity (in cSt).

The higher viscosity (higher cSt), the thicker the oil is at that temp. Compare both oils, use 40C as ref for cold start & 100C for warmed up engine. Thicker oil (higher cSt) = more drag on engine.

This is just a simple guide and doesn't take into account other variables that affects oil performance.

I normally use the above to find the "less thick" for the same SAE viscosity (eg xW30).

This post has been edited by Lanchio: Sep 28 2019, 03:00 PM

What is your oil change interval? 5k? 10k?

HX7 is semi-synthetic. Maybe the Castrol you used was fully synthetic. Any big brand name fully synthetic in the right viscosity will do fine in your car for <10,000km oil change intervals. Just buy the cheapest one from Tesco. Big brand name means Mobil, Shell, Castrol. Not Sumo or some niche racing brand.

The previously i used is castrol magnatex semi syn also and i change the oil every 7000 km. Do you think that popular oil such as Liqui Moly or Mobil 1 good for high mileage car??

Thanks for the detailed info 👍

Mobil 1 is definitely a good all rounder engine oil. But for your oil change interval, you can make do with any brand name fully synthetic. Save money.

There's fake Shell Helix engine oil in the market so be careful. Sure what you put in was genuine?

I bought directly from Shell petrol station tho

Noted
Btw, what oil you using now??

Shell Helix Ultra or Total Quartz fully synthetic, both from Tesco, whichever cheaper. Tesco don't sell fake engine oils, despite what people say.