Rotella oil

**kellen** · 10-13-2009, 05:36 PM

Originally Posted by frekeyguy

what type of motomaster oil are you using?

I used the four stroke 10w-40, whatever

**unL33T** · 06-24-2010, 08:52 AM

Bringing another oil thread to the top.

So my bike suggests 10W40 or 10W50 depending on the ambient temperature. I see a lot of people suggesting 5W40 Rotella T full synth. Wouldn't this be way too thin for my bike? I used to think that the lower the first number, the better. However in my car's manual it shows 10W30 as good for -25C to +20C but 0W30 is only good for -35C to 0C so I was mistaken about how it works (car recommended is 10W40 or 20W50 in the summer and 10W30 in the winter). I'm also wondering how 0W40 would fit into that equation for my car because I have an old 4L jug of 0W40 Esso XD3 from when I had a TDI that I want to use in something.

Or does the ratings of the oil really not have all that much to do with how well it protects the engine and it's more dependent on the brand/type of oil?

Really trying to figure out this oil thing. Never thought oil would be this complicated. I fail.

**frekeyguy** · 06-24-2010, 10:10 AM

Originally Posted by kellen

I used the four stroke 10w-40, whatever

i've tried the castrol gtx....bike didnt shift too well.

im back to regular rotella T....makes the trans seem like its swimming in butter

**hammakat** · 06-24-2010, 12:06 PM

My Katana calls for at least 10W40 but I just did an oil change with Rotella T6 synth 5W40 and have no worries. I care more about the second number then the first.

**unL33T** · 06-24-2010, 12:09 PM

Originally Posted by hammakat

My Katana calls for at least 10W40 but I just did an oil change with Rotella T6 synth 5W40 and have no worries. I care more about the second number then the first.

Yeah, like I said, I originally though the second number was more important but after looking at the chart for my car it really throws me off...

If there was almost no difference between 10W-30 and 5W-30 then why is the operating ambient temp so much lower for the 5W?

Of course that chart is 25 years out of date so maybe it's irrelevant now.

**sircastic** · 06-24-2010, 12:19 PM

The first number is the oil weight or viscosity when cold, the second is when hot. The lower the weight when cold the quicker and easier it starts moving through the engine when cold. The difference between a 5W and 10W is not something that's typically going to impact a bike ... they're both fine.

**bobjohnson** · 06-24-2010, 03:29 PM

Originally Posted by sircastic

The first number is the oil weight or viscosity when cold, the second is when hot. The lower the weight when cold the quicker and easier it starts moving through the engine when cold. The difference between a 5W and 10W is not something that's typically going to impact a bike ... they're both fine.

Yep. The low cold viscosity is actually better as long as youre not one of those dudes that revs the piss out of his bike the second you turn it on. The thinner oil will run up through the enginer faster than a thicker oil would when its cold. As long as you give it a few seconds to warm up and dont drive it like mad until the engines up to temp, itll be ok.

**bitzz** · 06-24-2010, 03:41 PM

The MOST wear on an engine is at start up.
So let's put oil in our bikes that is half as viscous as what the engine was designed for.

HMMmmmmmmmm
GOOD PLAN!

**SlowNLow** · 06-24-2010, 04:04 PM

Originally Posted by bitzz

The MOST wear on an engine is at start up.
So let's put oil in our bikes that is half as viscous as what the engine was designed for.

HMMmmmmmmmm
GOOD PLAN!

Sure, that same oil will reach the other components faster as well due to it's lower viscosity, thereby protecting those components quicker.... you couldn't tell the diff between the two oils, nor could your engine.

**bobjohnson** · 06-24-2010, 05:29 PM

Originally Posted by bitzz

The MOST wear on an engine is at start up.
So let's put oil in our bikes that is half as viscous as what the engine was designed for.

HMMmmmmmmmm
GOOD PLAN!

Most wear on the engine is at start up because the oil from the top end has sunk back down to the bottom. If the oil moves through the engine faster, the wear at start up is lessened.

At idle speed, there would be virtually no difference between a 10w and 5w oil. Its when you crank on it and things start reaching their tolerances that it matters.

Like i said, let it idle for a minute, and dont rip it until its warmed up. Basically what you should be doing anyway. If youre one of those guys that presses the starter and immediately cracks the throttle to redline, then takes off out of your driveway and redlines every gear on a cold engine, then yeah, you might end up with some problems. But id bet youd run into those same problems using a 10w oil as well.

**V-Tom** · 06-24-2010, 10:47 PM

To add to this: realize that the 5w when cold, is thicker than the 40 weight is when hot.

As far as warm up goes: if you bike is ridable there is no reason to idle for even a second or two. You have oil pressure moments after starting. Start it and ride away, albeit ride away gently and easily. Idling just isn't good for an engine and is way worse when it is cold.

If your bike needs a few minutes (say to get off choke or whatever) before it is ridable then of course wait, but if you have a bike that is fuel injected start it and go.

..Tom