Oil Viscosity vs Bearing Clearance

[omegaspeedy]

The 1.6L GDI engine does too if you read the RHD manual.

And to add, my New Zealand 2017 2.0 GDI Tucson allows a 50 grade per the user manual!View attachment 69373

Point *1 is interesting if you read between the lines. Hopefully there are no compromises with getting better fuel economy. Interesting in this case the 1.6T doesn't allow a 20. Cujet, yes good point you made Re chains. It's quite possible that the heavier oil will have benefits in that area.

 

[BMW Dom]

Point *1 is interesting if you read between the lines. Hopefully there are no compromises with getting better fuel economy. Interesting in this case the 1.6T doesn't allow a 20. Cujet, yes good point you made Re chains. It's quite possible that the heavier oil will have benefits in that area.

There of course is a compromise for better fuel economy.

 

[Yah-Tah-Hey]

The Toyota 2020 1GR-FE engine sold in Europe has an oil viscosity specification ranging from 5W-30 to 20W-50, which is a difference of 15 points in the first value and 20 points in the second. In the USA, Toyota recommends 0W-20 for my 1GR-FE engine. I think it will run just fine with 5W-30.

Absolutely Doug. Go for it.

 

[wpod]

Because we discussed it before, i just came up with the idea of checking all my workshop manuals for oil reccomendation and bearing clerances. Printed in the manuals are the follwing Crank and Rod bearing clearances, measurments in Millimeter:

1. Crank: 0.013-0.040 Rod: 0.028-0.052
2. Crank: 0.020-0.044 Rod: 0.032-0.056
3. Crank: 0.017-0.042 Rod: 0.030-0.054
4. Crank: 0.020-0.044 Rod: 0.042-0.070

Three of them are motorcycles where 10w-40 is recomended, one is a car where 10w-30 is recomended.

Could you tell wich ones are the bikes and wich one is the car?
While i was higly sceptical about oil viscosity and was thinking that thicker is not better, i start to re-think.

You will want oil thick enough to keep the parts separated in the most severe operation you will encounter. Going too thick will not add any more protection and will cost power

 

[ChristianReske]

Yes... but while the car in my list was specified for -30 oil, the motorcycles are specified for -40 or -50 Oil.

If you look at the clearances, i think it is safe to say that you are free to choose between 30 to 50 Oil for all theses engines.
I am meanwhile using -40 oil in the car and -50 Oil in the Motorcycle. The later one because the motorcycle is Nr. 4 in the list, the one with the biggest rod clearance.

You are right, using a 50 oil in the car or a 60 oil in the Motorcycle is useless in this case.

Makes we wonder about the bearing clearances of some newer cars that calls for 0w-16.

 

[Accent Abuser]

Yes... but while the car in my list was specified for -30 oil, the motorcycles are specified for -40 or -50 Oil.

If you look at the clearances, i think it is safe to say that you are free to choose between 30 to 50 Oil for all theses engines.
I am meanwhile using -40 oil in the car and -50 Oil in the Motorcycle. The later one because the motorcycle is Nr. 4 in the list, the one with the biggest rod clearance.

You are right, using a 50 oil in the car or a 60 oil in the Motorcycle is useless in this case.

Makes we wonder about the bearing clearances of some newer cars that calls for 0w-16.

They probably have wider bearings, many modern engines are already at the practical limit clearance wise.

 

[partspro]

I seem to recall the rotational bearing speed in the Ford 351 Windsor motor was so high over 58000 that oil would be thrown off the bearing, Cleveland’s had smaller mains for higher Rpms