[sc489]

My new Mazda 3 2.0 Sport petrol is due its first service in a few weeks. The Mazda handbook recommends the use of Mazda synthetic oils - Mazda Original Oil Supra 0W-20 (synthetic) or Mazda Original Oil Ultra 5W-30 (synthetic). My local dealer's service schedule offers only a semi-synthetic 5W-30 oil unless I specify the fully synthetic oil at extra cost. I do about 8000 miles per year of which 50% is long distance motorway trips at 70 mph. Please advise:

1. Which would be the most suitable oil for my driving style in the UK climate (typically -5 deg C to 25 deg C)?
2. Does synthetic oil offer any practical advantage compared to semi-synthetic oil for my type of driving?

 

[MeteorGray]

The practical advantage of the synthetic is the warranty. I do what the manufacturer wants to do as long as I have a warranty. After that, I do what I want to do.

As far as the oil weight rating, either should be fine.

 

[M3Nitro]

The temperatures you are operating in it is best to use only a full synthetic and 0w-20 (W=weather not weight) as per recommended until you are out of the warranty period. In the US unlike other counties we have what is calle the The Magnuson-Moss Warranty Act which allows us to choose things we use and have done regarding warranty.

If you are really concerned you can send a small sample of your oil in to be tested and a report generated which can really tell you everything you need to know about what is going on inside your engine and the oil you are using. It is 30.00 USD but you would need to contact them for all the information. I have used them for year and dozens of sampled oils both engine and transmission that helps me with preventing and also diagnosis problems.

I just sampled tested my oil at my new 2018 Mazda3 @ 3005 miles. It should all the normal items like Molybdenum and other items normal for a new engine breaking in and what is in the oil for the first few thousand miles.

I am a firm practicer of changing oil and filter at 5000 miles or less. Oil is cheap engines are not. I am by no means suggesting that other change their oil as frequent this is just me and what I do.

https://www.blackstone-labs.com/

^^^^^^^^^^^^^^^^^

 

[oscargamer]

0w20 synthetic

 

[RalphVa]

For best startup protection and still give you plenty protection at 25 C, the 0w20 synthetic is the best choice.

For the first change at 10k miles on our 2016 sGT (2.5 L), I put 0w20 M1 in it, and a M1 oil filter.

With your type driving, you could easily go over a year and change at 10k miles, but the manual says 1 year or 10k. To stay within the warranty, guess you have to change at 1 year. The 1 yr mark is really to cover their legal butts for the type driver who took it on very short trips and never really warmed it up in a year.

Ralph

 

[sc489]

Thanks for your help. My local Mazda dealer say they use Mazda Original Oil Ultra 5W-30 (fully synthetic) as standard for servicing. They can use 10W-40 at extra cost. I'm inclined to have the Ultra 5W-30 since it is recommended in the manual, cheaper and I drive carefully. Note we only get temperatures at 25 deg or higher in the UK for a few days each year!

 

[Odi]

Thanks for your help. My local Mazda dealer say they use Mazda Original Oil Ultra 5W-30 (fully synthetic) as standard for servicing. They can use 10W-40 at extra cost. I'm inclined to have the Ultra 5W-30 since it is recommended in the manual, cheaper and I drive carefully. Note we only get temperatures at 25 deg or higher in the UK for a few days each year!

You're fine with the 5w30.

 

[RalphVa]

Either 0w20 or 5w30 are okay, according to our owners manuals. The 0w20 would give you a little bit lower fuel consumption, due to less pumping losses. I went to 0w20 in our Tacoma pickup with less fuel consumption than 5w30. On it, it's near about 2 mpg, but it's a heavier vehicle (at 3500 #) than our Mazdas (probably prorates by weight). You can work out whether it would cover the extra dealer cost.

Ralph

 

[Stewie]

0w20 winter and 5w20 summer

 

[RalphVa]

0w20 winter and 5w20 summer

NO. 0w20 year round. Only change ours once/yr.

Ralph

 

[RalphVa]

I once owned a VW Cabrio that had hydraulic valves that would drain down. The ONLY oil that would fill the hydraulic valves (even in summer) was 0wxx. 5wxx wouldn't pump in quick enough to stop the hydraulic knock.

0w20 is completely adequate all year round unless you're racing the car. Then maybe consider 5w30 unless you need full engine rpm right away. Then use 0w30 or 0w20. F1 engines run 5 and 10 grade oils at 15,000 rpm.

Ralph

 

[Stewie]

NO. 0w20 year round. Only change ours once/yr.

Ralph

0w20 is too thin for summer YMMV

 

[arathol]

0w20 is too thin for summer YMMV

Why? That is what is specified by Mazda....

 

[Stewie]

0w20 is too thin for summer YMMV

Why? That is what is specified by Mazda....

Mazda also says not to replace ATF and it is sealed for life. Are you gonna believe them?

 

[arathol]

Mazda also says not to replace ATF and it is sealed for life. Are you gonna believe them?

Yes. The engine was specified to use that oil by Mazda, its what is required to satisfy warranty requirements, I don't see the issue. 5w30 is specified for hot climates such as Central America, but North American cars use 0w20. The tolerances in the engine are such that thicker oil may not be able to get to certain places when cold if you use thicker oil.

 

[oscargamer]

0w20 is too thin for summer YMMV

No it's not.

 

[RalphVa]

I agree.

Do not believe those bar charts that show maximum ambient temperatures by oil grade. Your engine runs around 190-220 F, as set by your coolant thermostat. Unless you do very heavy duty driving such as racing in hot climate, the specified 0w20 is fine.

A 0w20 oil will actually be slightly MORE viscous above 100 C or 212 F than a 5w20 oil, if they're both at mid points in the spec range or measure the same at the 0 spec and the 20w spec. The 0w20 has a flatter viscosity/temperature line than a 5w20.

Ralph

 

[M3Nitro]

The "W" in oil mean winter not weight
Motor oil is chosen by its viscosity, performance rating and material ingredients first and then everything else.

Most Auto Manufactures Warranty stipulates that the maintenance schedules be followed for warranty coverage and requirements with some parts or systems, this does not always mean that any specif brand part be used to cover the warranty. They can recommend part brands worded as an example "Use Genuine MOPAR Parts" and they can require specif procedures be followed. Any substitution of parts must meet the minimum requirements or what is called OEM specifications as it is often advertised by aftermarket parts to complete and be covered for the Auto manufacture warranty. This has long been established since The Magnuson-Moss Warranty Act in the UNITED STATES to protect consumers should they choose to use service centers and other parts other then from the auto maker and Dealerships and not fear losing their warranty coverage. I do recommend always carefully and thoroughly read the complete warranty information having to do with your vehicle and not rely on forums for legal guides for warranty coverage.

Motor Oils, the wording is playful from many auto manufactures because the recommended oil for many newer engines is to achieve the best possible *MPG, many as an example may use phrases like to achieve the best *performance use BRAND-X. Operating environments ultimately determine the appropriate or best motor oil choice for maximum engine protect and use.

 

[arathol]

Most Auto Manufactures Warranty stipulates that the maintenance schedules be followed for warranty coverage and requirements with some parts or systems, this does not always mean that any specif brand part be used to cover the warranty. They can recommend part brands worded as an example "Use Genuine MOPAR Parts" and they can require specif procedures be followed. Any substitution of parts must meet the minimum requirements or what is called OEM specifications as it is often advertised by aftermarket parts to complete and be covered for the Auto manufacture warranty. This has long been established since The Magnuson-Moss Warranty Act in the UNITED STATES to protect consumers should they choose to use service centers and other parts other then from the auto maker and Dealerships and not fear losing their warranty coverage. I do recommend always carefully and thoroughly read the complete warranty information having to do with your vehicle and not rely on forums for legal guides for warranty coverage.

This is true. When all else fails, RTFM. Its says most of what is above right in the owners manual-:smile2:

 

[BrianU]

I've been running 5W-20 in Hondas since 2004, now my dealer uses 0W-20 Quaker State Ultimate Durability. I live in Houston, Texas and have no concerns with using these modern synthetic motors oils as specified by the manufacture (OEM). I believe Mazda recommends using a 0W-20 weight oil that meets "ILSAC GF-5".

For anyone that know better than the OEM, use what you like at your own risk!