Hi there, thanks, by what i know is 5W 40 should be lighter but in my experiance, 5w 50 seems to be more better, let me share my Vios experiance, after 5K service, toyota SC started to use Toyota 5W 40 fully synthetic OIL, after warranty expired for the car, i change to 5w 50 which is a mobil 1, tell u i feel the car more lighter and more powerful yet more smooth and less engine noise, ideally u wont hear any engine noise when u waiting in traffic light, hehehe, thats why i think 5w 50 should be more powerfull and smoother than 5w 40, but i may be wrong here because Mobil 1 and toyota is diffrent brand, further to add,  for my Elantra i'm not going to change it on my first service, planing to wait for the next 5000 service an hantam my Mobil 1 5w 50 on it, Hopefully the car wont fly  hehe, just kidding...

Does the Oil really does what it says, afraid to test on my car lah bro, if anything goes wrong, pening lah...., have u tested it on ur vehicle ???

Thanks allot for the info bro, that's rite bro, Engine Oil makes allot different, u check back my edited reply, hehe, i missed out something earlier, i does see the point u are trying emphasize after i looked the website for 2nd time, see how lah bro, i will go check out the Mobil 1 5w 30 Oil for my 5K service, sure expensive, because last time my 5w 50 cost me RM185 - 195 depends on the shop, between my fren he is good in this type of car things and very informative guy, he told me, no mater its semi or fully the shell helix is still heavy compare to other brand, so myself am not fan of shell either, now a bit afraid of that engine oil that hyundai using,

my recommendation for petrol try use caltex ron 95, if you are using shell, u will find the car more powerful and will move much more easier compare to shell petrol, check out and see

I am using SHell 10w40 too..it's recommend by the one of my mechanic's friend..

Hi hks, I'm not very good in this, but from my understanding the first digit define the type I guess, 10 is for semi syntethic and 5 is for fully synthetic, in general fully synthetic is much lighter than semi synthetic, about the 2nd digit, it defines how lighter the oil is, the lower the digit the more lighter it is, for example 5w 30 is more lighter than 5w 40, this applies for semi synthetic also, please check this with local mechanics, I might be totally wrong on the first digit explanation, hi guys plz correct me if I'm wrong, thxx... 

bro, u had change to PC fuel oil right? How do u feel? OK?

Tet Tet sound? the sound only come after using PC or its been there since day 1?
Mine no sound even cold start after 2 days leaving it.
Maybe will rev up a while but will come back down below 1K after few secs.

You know the market trend of local fuel oil bro .. good 
Cause not many ppl know what is happening at the back as every where ppl are promoting the local brands.
But not just local brands, even some oversea brands like Sum0, HK5, Lub3 or R0ck also don't really has a spec sheet for you to see.
Makes you wonder what they put inside the oil. 

Bro, yours is 1.6 auto/manual or 1.8 ???

I like to start my engine/car every morning and let it run for a min before moving.
I will not turn on the radio and air cond till i hit highway.
So i can observe any farnie sound or irregularities from the whole car.

You should get the compressor check bro.
Our car damn quiet during stationery without the radio on with air cond on level 1.
If air cond off, damn i dun even know the engine ON or not .. haha! 

Your FC 450Km for Rm 70 is quite good bro, are u getting this from the beginning, i mean even on the first 1000 ? or after first service ?, between this 450KM is fully city or highway or combine drive ??

Yo Boss, thanks allot, really helpfull, i'm considering the Potent boost, waiting for the guy to reply me the price, thanks allot again man....

You r driving 1.6 or 1.8 bro?
If 1.8 go ahead but if 1.6 n u r looking for better FC well sadly it's not really that much diff.
Well unless u can live with a very slow car.
As we tested before the potent are meant for 1.8 as their torque or power is higher.
So even when they set to EC mode, the car at low rev but still can give sufficient power.
This is not the case for 1.6 which has lower hP.
If u r looking for acceleration then go ahead 
This is what I discovered from our road test for 1.6 unit previously.

humm, speed is still not so much considered for me as i found the car now move much more faster, i serviced the car after 1000 Km, i wanted to use the Shell semi synt they use, but still no good feel about it, so i bought my own Mobil 1 10w 40 semi synt, guess what, they car more faster i mean, less throttle to shift between gears, the pickup was very good and smooth, seems like the FC as improved, now the car at 1 bar before half tank showing 200 Km, as what i know, it was 75% city drive and 25% highway, hopefully can mark a good consumption throughout full tank

Ya true, that's why i choose a good oil, don't want to use bad oils, between i bought the Mobil 1 from tesco, so sure not recycled 1...

bro, make sure when u shift be gentle a bit on the paddle, watch the green eco light, make sure it is not turning off for long, try to make the eco light stays as much as u could, if u feel car is needing allot throthle to move, than something wrong, on your first service complaint to them, i did, even thou i got over 430++ average on that first  mineral engine oil, i still complaint because what simedarby claim on their website is totally misleading, they stated combine fuel consumption of highway and city will result in 14.1km/lit, that not even come close to what we are experiencing on real life, so i made a complaint they said they can't do much and they reset my ECU and upgraded to new a 1, i still remember when i saw the computer box they use to connect to the car shows 4 new ECU, everything have the word IMPROVEMENT, but can't really see what was the improvement about, so the service person used the latest ECU it has, some-more i use Mobil 1 10w 40 Semi synthetic, not the shell helix 7 that they recommend, another thing to take note, for petrol don't use shell or petronas, i recommend u use caltex 95, use it to flush out the carbons in ur engine, caltex are good in cleaning ur engine, once u finished up with caltex, u can use petron, that should give good power and fuel almost on par with caltex, seriously say no for shell and petronas for this car, use caltex and see for ur self, u will notice immediate power difference on ur pickup(torque)....

Best quote I heard "shell i never hear any good comments(no wonder alonso lost to vettel)"   

I also wanna change to other brand actually but it seemed like i am too get used of using it (and also because of collecting the Bonus Link points  )

For my car, I had just tried Shell and Petronas. Didn't tried BHP or Petron yet.

Maybe for my wife new car, will give Petronas a try and see how it goes since same engine as ours 

Yup, u r right. The quality of the engine oil do play a part of the FC/Power with the petrol we pump.

With the bad quality of our local petrol ron95 etc .. it's actually crucial to use a good engine oil to help protect our engine and filter out the carbon.

Mine FC is really worst..been driving the car for almost half year.. 42L petrol can only last for 360KM Max... everytime I pump full tank RM80.. the MFD will only show 400KM availabe ( last 50KM will drop fast and show none). the petrol consumption is on par with 408T