Rotella 5 40 or 15 40

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Maybe you all can help me I'm not sure what oil to use in my suzuki gs 500 Air cooled. I'm 50-50 between the Rotella T
5-40 syn. and the 15-40 from the research on this site it seems it's a toss up, I live in a cooler aera MN so I'm thinking 5-40 any help would be great.
 
The primary arguments for synthetic (the 5W-40) are:

1 - Cold temperature flow properties
2 - Ability to extend change intervals
3 - Slightly higher flash point
4 - Enhanced fuel economy

For Minnesota, I would think #1 is your primary consideration. The 15W-40 is rated down to about 20 degrees F. The 5W-40 down to something in the negative range.

(The upper range is about the same for the two -- into the 120 degrees F ambient outside temperature.)

I'm going to guess that fuel economy benefits are small -- a percent or two. That can make a difference to a million mile truck, but probably not to a Suzuki GS500.

As for #3 -- flash point -- I'm no expert, but I'm not convinced this makes much difference between the 15W-40 and the 5W-40. Shell would not market the 15W-40 if there was a risk of serious oil degradation at higher internal temperatures. My point being -- I doubt your GS500 is going to suffer from the 15W-40.

The extended oil changes are what most people think about when they think synthetic. In any event, you should UOA your oil before simply assuming you can extend OCI with the 5W-40.

I live in Tucson, and I run 15W-40 year round. I have a water-cooled Goldwing.
 
Rotella 5W40 is my Winter pour. My bike sits in the garage from the first of December until the end of March. Those 4 months, it sits with brand new oil in it, as Rotella is outstanding to keep down those acids that tend to build-up. It generally gets one or two start ups and 20-30 mile rides each of those 4 months.

Amsoil guy here for the rest of the year....and oh yeah....ONE OCI for 8 months!!!

By the way I don't want to start a fight, but I think Mobil DELVAC 1300 15w40 is a little better oil than Rotella 15w40. We pour DELVAC in our two Honda XL600's every 2k miles. With that said, Rotella dino or synthetic are awesome oils as well.
 
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Yea, I think i'm going to run 15-40 in spring summer then for winter change over to 5-40
 
+1 for the Rotella 15 40. That's what I run in my air cooled v star 1100. shifts great, no problems and It's $9 cheaper per gallon than the 5w 40. I do plan to run the 5w 40 in the winter though.

Get the 15w 40 and treat yourself to a value meal with the money you save!
 
Originally Posted By: BigJohn
By the way I don't want to start a fight, but I think Mobil DELVAC 1300 15w40 is a little better oil than Rotella 15w40.

crazy2.gif
What??!!
crazy2.gif


Why, that's blasphemy, sir!

wink.gif
 
Originally Posted By: BigJohn
Rotella 5W40 is my Winter pour. My bike sits in the garage from the first of December until the end of March. Those 4 months, it sits with brand new oil in it, as Rotella is outstanding to keep down those acids that tend to build-up. It generally gets one or two start ups and 20-30 mile rides each of those 4 months.

Amsoil guy here for the rest of the year....and oh yeah....ONE OCI for 8 months!!!


You are wasting your money on the Rotella. That Amsoil has a high enough TBN to go all year or 5000 miles. I have seen a few guys go 2 years on it and still have a TBN of 4. Try filling at lay up with the Amsoil and send in a sample after Winter.
 
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Originally Posted By: PT1
Originally Posted By: BigJohn
Rotella 5W40 is my Winter pour. My bike sits in the garage from the first of December until the end of March. Those 4 months, it sits with brand new oil in it, as Rotella is outstanding to keep down those acids that tend to build-up. It generally gets one or two start ups and 20-30 mile rides each of those 4 months.

Amsoil guy here for the rest of the year....and oh yeah....ONE OCI for 8 months!!!


You are wasting your money on the Rotella. That Amsoil has a high enough TBN to go all year or 5000 miles. I have seen a few guys go 2 years on it and still have a TBN of 4. Try filling at lay up with the Amsoil and send in a sample after Winter.


At $40.00 a gal. I think I'll pass on the Amsoil
 
yeah here locally we can get 3 gallons of Rotella T 15W40 for $27 + tax. Don't think I am wasting my money esp when you have frequent OCI's (best practice w/ a wet clutch and shared sump)
 
I haven't tried the Rotella 15-40 yet, been running the 5-40 synthetic since new for about 12K miles. I've been doing 3-5K on OCIs, changing the filter to a new PL14610 at the same time. Probably overkill on the OCIs and especially the filter changes. The oil looks very clean when it comes out, and feels really good still, but I do notice the shifting gets scratchier around 3K or so. That's why I think I might try the 15-40 next summer--from what I read here it has better sheer resistance. The problem is that I usually do a change before the winter lay up, then I ride that oil in the spring until about mid-summer. So I probably won't get to experiment until June or July 2010! With the 5-50 it starts right up, even in the middle of the winter with the temps around freezing. Even though it gets a lot colder than that here, I don't start the cycle unless we get a warm day in the 30s. Usually run it once or twice over the winter up to operating temp for awhile, just to circulate oil and gas.
 
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