I was thinking about trying 10W-50 in the hotter weather. Is this a bad idea?

Matt

 

I would stick with the recommended weight oil. I think my dad uses 50 weight oil in his diesel truck.

 

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u need to host the picture

 

I use Mobil 1 10w30 year round. I think 15w50 would be too thick unless you live in an area where it's over 100 degrees a lot of the time.

 

Hey guyz.. was wondering... I use Mobil 1 also. But everytime I get a oil change the proformance of my car isn't that of a great response. It takes at least 100 miles to get adjust. Is that suppose to happen? Does that happen to you guys? The only difference I notice after an oil change is that when you gas its very smooth. Let me know what u guys think thanks

-BEEF

 

M1 15w-50 (they don't make a 10w-50) is not necessary and would only serve to increase friction/heat and reduce power, mpg and realtive oil flow; further, it is not a Nissan recommended viscosity. M1 10w-30 is plenty good to protect in even extreme street conditions....as is Amsoil or Redline in the same weight.

 

Yeah, I meant 15W-50. I live in Florida so I was thinking that maybe thicker oil would be a good idea.

 

M1 10w-30 year round.

 

i'm on 10-30 now, but am considering 5-30 for the winters. tho in Los Angeles, i don't even know if that's necessary.

 

Hey Guys,
I used to supply synthetic basestocks to Mobil and Redline so have had a lot of experience with synthetics all the way back in the early '80s. All engines today have much tighter clearances internally than in the old days so viscosity is much more critical in a modern engine. The oil lines, and especially the bearing surfaces are all built around a specific viscosity measure, in our case 5W-30. You CAN run a 10W-30, especially in hot climates, but under no circumstances should you run a 15W-50 in a Max engine. What will happen is under extreme conditions the oil will be too thick the be pumped into a micromiter thin bearing surface and you will have microscopic metal-to-metal wear, not a good thing.

Synthetics are not like regular oils, they keep their rated viscosity over a much broader range of temps than dino oil. I run 5W30 Mobil 1 only, summer and winter and know that my engine is protected. Only in a very high mileage engine would I consider a heavier rate oil, bearing clearances increase with wear to the point where a higher vis oil will help. Otherwise, stick with 5W30 synthetic, you'll treat your Max right!

 

HEY! Who asked you to interject FACT to this?

 

If you look at the product data sheets for M1 5w-30 and 10w-30 they are almost the same with a slight variance at the lower viscosity rating. M1 10W-30 is more sheer stable than their 5w-30 and that is why I use it over their 5w-30. Now if you are talking dino oils, then yes, I would stick with 5w-30 unless it is a high milege car. But M1 10w-30 has lower viscosity measures at both 40 and 100 degrees C than most all non-synthetic 5w-30 oils.
Also, maybe Mobil bought synthetic basestocks at one time many years ago but for the last 15 years they have been and are one of the largest suppliers of synthetic PAO basestocks in the world, not a buyer. They supply the likes of Amsoil and others with high quality PAO synthetic basestocks.

 

You are correct about Mobil being a major supplier of PAO basestocks, Mobil used to buy diester and mainly polyol ester basestocks from me for use in Military specification jet aircraft turbines. At extreme temp performance requirements of military jet engines, PAOs are not sufficiently stable at the high end compared to polyol esters. Viscosity Index Improvers (VIs) are what "sheer" when you talk about sheer stability, synthetics have a much flatter and consistant inherent viscosity index than dino oils, so much less of this long chain is needed to result in sheer to begin with. Yes, there probably is a tad amount more of VIs added to 5W-30 the only real difference between the 5 & 10 base weight is a slightly smaller chain length is used in the 5W-30. The amount of additional VI added to 5W-30 is inconsequential in terms of sheer to appreciably reduce viscosity at high temps as long as you stick with a 7500 mile change interval.

There is also a disadvantage to a 10W-30 compared to 5W-30, that the wear during the first 10 seconds at startup, especially on cooler (or cold)start-ups. Synthetics tend to coat and stick to internal components much better than dino oils, which helps while cold cranking. Once the engine kicks over, the stress load increase significantly due to engine firing. the oil pump pushing against thicker oil may not in the first 10 seconds have the ability to bring the oil up to maximum flow as quickly, thus increasing wear. the 5W reaches full pressure 2x as fast, and the Max's engine and oil pump is designed for this viscousity oil.

The lighter viscousity also will slightly increase fuel economy, as it reduces friction better and the pump has to work less hard. In the old days with dino oil the extra film thickness was good to have to reduce friction, in a modern engine with tight toilerances and using a high quality synthetic like Mobil 1, you get less friction and better engine performance with a lighter vis 5W-30. I would recommend against the 0W30 that Mobil is promoting for fuel economy; with this product your film thickness may be too thin to protect, especially if you are pushing the engine (if you don't, what are you doing on this forum!?!)

Whew, that felt better!

 

Agreed and now understand the type of esters you sold especially to Redline who uses these in their oils vs a PAO basestock. My only point of clarification is, that with synthetics, the low temperature pumpability and flow of M1 5w-30 vs 10w-30 is nominal; however, this is not so with dinos. Based on the UOAs I have seen on M1(ie., wear metals and ability to stay in grade), I would still use 10w-30 over the 5w-30 in almost any temperature absent the rare case where temps are below -20 degrees. With dino oils, I fully agree for the reasons you mention that 5w-30 should be used over 10w-30 unless the engine has over 100K miles.

 

The should be no real reason to use anything over 5w30 on these engines unless you are turbo/super charged and want piece of mind. Only then would I get an oil cooler or go to 10w30. The heavier oil will cause your oil pump to fail and you will lose some hp because of the drag of using heavier oils. 5w30 is good for all seasions and will protect engine parts accordingly.