Is A7/B7 the new A5/B5

[SureshR]

A5B5 is a one size fits all for non scr/nox gas and diesel small engines. 5w20 in that is one size fits all along with more fuel economy than the earlier spec of 5w30.

True Mustang says 5w20 for street applications but if someone drives a mustang like a soccer mom driving a kia soul I’d be surprised so a thicker weight oil won’t be a bad idea. Just go with a good 5w50.

 

[yowps3]

This reminds of that infamous H/K "ACEA A5 or Higher" oil recommendation.

After all these years, not sure if anyone has worked it out yet?

 

[arizonaSummer]

A5B5 is a one size fits all for non scr/nox gas and diesel small engines. 5w20 in that is one size fits all along with more fuel economy than the earlier spec of 5w30.

True Mustang says 5w20 for street applications but if someone drives a mustang like a soccer mom driving a kia soul I’d be surprised so a thicker weight oil won’t be a bad idea. Just go with a good 5w50.

Don't you go by this train of thought:

"Since thicker oil doesn't transfer heat as well as thinner oil, operating temperatures will increase, possibly leading to accelerated chemical break down (called “oxidation“) and harmful sludge and deposits."

Also the tolerances of a new engine are very tight, should I not move to a thicker oil when the engine has X thousand miles on the clock

 

[arizonaSummer]

I think I will be using Valvoline SynPower FE 5w-30 A7/B7 after break-in, reading the posts on this thread. Thanks chaps

 

[Bailes1992]

My take from this is A7/B7 is an alternative spec and not meant to replace A5/B5. Simply has some improvements applicable to DI engines, which the Mustang 5.0 is not.

M1 0w40 FS would be my pick but can be expensive here in the UK.

I do like Fuchs Titan XTL Flex 3 which I have in my Duster at the moment. It's a 5w40 ACEA C3 oil that has a load of manufacturer approvals including the rather stringent Porsche C40. Think I paid less than £35/5litres last time I bought it.

 

[kschachn]

Don't you go by this train of thought:

"Since thicker oil doesn't transfer heat as well as thinner oil, operating temperatures will increase, possibly leading to accelerated chemical break down (called “oxidation“) and harmful sludge and deposits."

Also the tolerances of a new engine are very tight, should I not move to a thicker oil when the engine has X thousand miles on the clock

Good old tolerances. It just keeps on going.

 

[Bailes1992]

Don't you go by this train of thought:

"Since thicker oil doesn't transfer heat as well as thinner oil, operating temperatures will increase, possibly leading to accelerated chemical break down (called “oxidation“) and harmful sludge and deposits."

Also the tolerances of a new engine are very tight, should I not move to a thicker oil when the engine has X thousand miles on the clock

I think you mean clearances, not tolerances.

And they have not changed in 50+ years. Thinner oils are just for fuel economy and emissions.

 

[arizonaSummer]

I think you mean clearances, not tolerances.

And they have not changed in 50+ years. Thinner oils are just for fuel economy and emissions.

Going by this, a thicker oil will always provide better wear protection, and will not be too viscous for the pump?

 

[Bailes1992]

Going by this, a thicker oil will always provide better wear protection, and will not be too viscous for the pump?

Within reason, yes.

Think of it this way, your 5w20 oil is massively thicker at 5°c than a 0w40 or 5w40 would be at 50°c, let alone 100°c.

There's Ford Coyotes all over the US fitted to trucks that see nothing else but bulk 15w40 or 10w30 mineral oil and live long long lives. Don't overthink it.

 

[BMWTurboDzl]

Going by this, a thicker oil will always provide better wear protection, and will not be too viscous for the pump?

No. Automakers have done a great job at installing fear in consumers over the idea of using slightly heavier grades.

 

[kschachn]

No. Automakers have done a great job at installing fear in consumers over the idea of using slightly heavier grades.

As they are required to do per their CAFE award letter. It’s a lot more that than the manufacturer themselves, I don’t think the manufacturers are quite that stupid.

 

[arizonaSummer]

What is your opinion on pao + esters as a base vs mpao base

 

[OVERKILL]

What is your opinion on pao + esters as a base vs mpao base

You can't use mPAO as the base, it's too heavy. It's used to bring viscosity up (act like a VM) and keep Noack down.