Hi Wkc,
Wow , a very clean and clear 7400 km blotter spot from Helix H7 5W30.
There is absence of perimeter ring center zone.
Generally not much of contaminants and combustion by products in 7400 km usage as dispersion zone is not greyish , indicating engine is in tip top condition.
At outermost zone, there is an indication of fuel dilution either caused by cold sample or injection system. I suppose Mazda3 (Is it 2.0L ?) comes with direct injection, I would attribute this as the main cause.
Having said this, in contrary to popular belief UOA's of say, <20/30000 km have shown that most fuel dilution incidences do not cause increase in metal wear (in ppm) though there is obvious drop in viscosity.

In your case , follow mileage will do , not time as we always heard as Malaysia never had winter or for that matter spring/autumn where cold temperature promotes corrosion.

You may consider using a cheaper semi synthetic for 2 years of 10,000 km usage, IMO.

Note: Our minimum ambient temperature is 24*C, vs gwailous winter temperature up to -40*C or lower , go figure.

Note2: I had seen a few UOA's of  4-7 year old used engine oils on Bitog that demonstrates tip top condition.

Thanks for your feedback. Would driving conditions matter? Say, short trips of <10km daily.

Short trips is not favourable for long OCI, especially in countries with cold winters.
Now for our hot climate , the 'negative' is marginal IMHO.
For those of you not comfortable with (Euro) semi synthetic OCI > 10,000 km in normal circumstances, may be you can consider 8000 km or 2 years.
As I'd done > 16000 km OCI with Total Euro  Qaurtz Energy 10W40 semi synthetic in Avanza before , I would be comfortable with 10000 km or 2 years with short trips.
15,000 km ? .... I'm not comfortable , for now.
Anyway, in lieu of exorbitantly expensive  and time consuming UOA, a simple and cost free blotter spot test would be my option to push the limits beyond 10,000 km.

Just started reading thru this topic,  quite educative & nice exposures there bro.
After doing the blotter test and review for quite some time,  whats the best fully syn & semi syn EO that you think you would recommend? Just ur opinions..

zeng

Blotter 4 days ago, please help me do a reading of used oil blotter on my mazda3.

Shell helix hx7 5w30 semi synthetic
Oil mileage : 7400km (5 months)
Car total mileage : 60890km

[attachmentid=10168479]

Are you using RON 95 or RON 97 ?
Have a read on Mazda3.

A bit free so I want to update you guys on the latest blotter test I've taken from the current Honda Fully Synthetic SN0W30 engine oil as below.

@ 3,222KM

@ 4622KM

The perimeter ring of centre zone disappears in later blotter spot sample, which is good news indicating detergency/dispersancy properties of this Honda oil is still strong.
Unable to figure out why do earlier 3222 km sample  demonstrates some signs of perimeter ring that disappers in longer use ?
Generally later 4622 km sample is more grayish, indicating higher amount of combustion by-products and that's normal for an oil in use longer, IMHO.
Looks like this used Honda 0W30 is good to go for another 2000-4000 km and then see how the blotter spot develops.

I think I know why there's a perimeter ring on the first (3,222) blotter test. That's because I let the drip of oil dry up without moving it around the paper.

On the 2nd test, I basically turn the paper in a circular motion to spread the oil more evenly.

Your second method is not the correct method. You actually want to see how well the oil can bring particles to the edges. So your second blotter test should be invalid

I think I know why there's a perimeter ring on the first (3,222) blotter test. That's because I let the drip of oil dry up without moving it around the paper.

On the 2nd test, I basically turn the paper in a circular motion to spread the oil more evenly.

Your second method is not the correct method. You actually want to see how well the oil can bring particles to the edges. So your second blotter test should be invalid

What do you think ?
[attachmentid=8469303]
https://bobistheoilguy.com/forums/ubbthread...s_oil_change_up

A1.1) Round 1: Total Quartz 7000 Energy 10W40 SL/A3B4 in 2005 Avanza 1.3L K3-VE
A1.2) Blotters for :12,238 km ; 13,000 km ;13,673 km ; 14,218 km and 16,593 km
Note:Finally oil change at 16,631 km (10,334 miles) in early May 2017 after 9 months in use.
Fuel in use:
Mostly use : (Brand/RON#)  BHP RON 95 ;
Mixed with : (Brand/RON#)  None

A2.1) Round 2: Total Quartz 7000 Energy semi synthetic 10W40 SL/A3B4 in 2005 Toyota Avanza 1.3L K3-VE
A2.2) Blotters for : 5,087 km; 8,665 km ; 10,616 km ; 13,478 km and 15,000 km
Note:On 31 Jan 2018,after 9 months in use,this oil is replaced by fullsyn Shell Helix Ultra 5W40 MB 229.5

A3.1) Round 3: Shell Helix Ultra Full Synthetic 5W40 A3B4,MB 229.5,LL01,VW 50200 50500 in 2005 Toyota Avanza 1.3L K3-VE
A3.2) Blotters for :5575 km;10099 km;14100 km ;17138 km

E1 )Total Quartz 7000 Energy 10W40 semisyn SL A3B4 :-
a)  16,593 km ODO 247k, in  2005 Avanza 1.3 K3VE MPI ;
b) 15,000 km ODO 262k, -ditto-.

Aisin
5W30a )Aisin FS 5W30 (non-PAO) 13536 km and 14990 km  in 2002 Hyundai Elantra 1.8L G4GB @alphaz;

5W40a )Aisin FS (PAO+Ester) 5w-40 SN 12000 km in Elantra 2.0 NA (G4GC),ODO 194k km @speedy3210
Bardahl
5W40a )Bardahl MXP 5W-40 FS 4322 km, ODO 173k;6829 km, ODO 180k in Nissan Livina 1.6 NA @ putra23

Castrol
10W40a )Castrol Magnatec 10W40 SN 1537 km, ODO 234k km in 1999 Proton Wira 1.3 Fuel Injection ;

Honda
0W30a )Honda HMEO Fully Synthetic 0W30 3000 km;4000 km in 2011 Honda City,ODO 101,000 km @ cempedaklife

0W30b )Honda Fully Synthetic 0W30 3750 km in 2011 Honda City,ODO 107,750 km @ cempedaklife

0W30c )Honda Fully Synthetic 0W30 3222 km; 4622 km in 2010 Honda City L15A7,ODO 103k km @ Thrust;

Mobil
15W40a )HDEO Mobil Delvac mineral MX 15W40 (CJ4) 740 km/20 hours of track time, in KTM RC390 Motorcycle @e-lite;

Pennzoil
5W40a )Pennzoil Platinum Velocity 5W40 100%-synthetics 9900 km ,ODO 69k;17000 km, ODO 86k ;22000 km, ODO 91k in 2014 Myvi 1.3 K3VE EFI @Senscents;

Perodua
5W30a )Perodua SS 5W30 SM gold bottle 5000 km,ODO 133k;7000 km;8000 km in Kenari 1.0L @ahsam1212;

PetroCanada
0W30a )HDEO Petro Canada Duron XL 0w30 (API CH4/SJ) synthetic blend, 12707 km  ODO 283k,  in Nissan AD Resort 1.6L GA16 carburettor @chemistry;
15W40a )HDEO Petro-Canada Duron semi synthetic SHP 15w40 (CK4,E9,ECF-3) 11145 km ODO 295k ;12558 km ODO 297k, in Nissan AD Resort 1.6L GA16 carburettor @chemistry;
Petronas
10W40a )Petronas Syntium 800 SS 10W40 SN 4181 km in Toyota Vios NCP 42, Engine: 1NZ-FE ,ODO 189k km @XinG;
Shell
5W30
a )Formula Shell 5W30 "fullsyn"(?) SN GF5, 8500 km ODO 323k, in 1997 Wira 1.5 auto 4G15 carburrettor @Senscents;

b )Shell Helix Ultra Fully Synthetic 5W30 A3B4 (Made in Hong Kong) 10060 km; 14160 km ;15999 km  in 2002 Hyundai Elantra 1.8L G4GB @alphaz

c )Shell Helix HX7 semi synthetic 5W30 SN A3B4 7400 km ODO 60890 km , in Mazda3 @wkc5657

10W40
a )Formula Shell 10W40 mineral SN ,5466 km ODO 395k km, in 1999 Wira 1.6 MPI @speedy3210;

ATF Blotters
Toyota Type IV 32138 km in 2005 Toyota Avanza 1.3 automatic transmission;

UOA/VOA:
VOA Shell Helix Ultra 5W40 (Russia)
Z) Further readings:

On Site Oil & Fluid Analysis
Blotter Spot Test Helps Improve Engine Reliability
Sample Preparation and Test Procedure: A Quick Guide
Evaluating Lubricant Dispersancy
Chromatogram Patterns
Motor Oil Testing On The Cheap
ASTM D7899
Condition-based Lubricating Oil Change
One Drop Instant Lubricant Test

Where do u buy the chromatographic paper n how much bro ? Been using look at color n sediment in oil for oil changes....  

@zeng, What is your take on the limitation of the oil filter?

Say, the manufacturer allows for 10,000km, oil and filter change.

However, based on your expertise, the oil can go further, e.g. 15,000km.

Any change to the oil filter? would that then limit the extension of oil change interval?

Hi Jamespaul,
During 1970/80's , local OEM SC's had been recommending oil filter life of 10,000 km (i.e 2 oil changes @ 5000 km) till todate with use of API SE/SF oils and obsolete manufacturing technology such as 'metal finishing' on contacting components like crankshafts, camshafts, piston rings and piston liners.

As I understand it some (not sure if it's all) Europe VW and MB recommends 30,000 km oil change with Long Life oils like VW 50400 50700, MB 229.5, MB 229.51 etc but not sure about filter change intervals unless some readers can confirm it.

There maybe a 'progressive' OEM SC in KL recommending 15,000 km filter change coinciding with oil change,I don't know and I would like to know if there is any local OEM SC recommending 2X10,000 km or 2X15,000 km filter change.

I'd personally extended filter change to  17,138 km as per my blotter spot tests here with 280k ODO and I strongly believe my blotter is 'clean' enough for extending further filter change interval.

Instead of theorising and speculating on this one may spend chunks of money on UOA and Particle Counts or a  cheapo blotter spot test for better 'feel' .

Edit:With my limited knowledge on how oil filter works in our cars, I don't buy the concept of extending oil change interval by replacing oil filter  mid way of OCI.
I wouldn't be surprised if 30,000 km filter change interval is recommended in Europe, IDK.

From what I understand, European cars with extended OCI are using Fleece filter, which lasts up to 40,000km. So, they are fine for 15k to 25k km OCI

I understand that Japanese makers are using cellulose or paper, so hence, I was clarifying with you on if this could be the limitation.
Thanks!