Dodge SRT Viper Forums : ViperAlley banner
1 - 11 of 11 Posts

·
Premium Member
Joined
·
3,357 Posts
Discussion Starter · #1 ·
The subject says it all... what does everyone like in terms of weight/viscosity? I can get a good price on the big jugs of Mobil 1, so that's the brand I'm sticking with, but I've heard widely varying opinions on what I should run, and whether I should use the same thing for regular street driving.

Bear in mind I'm in FL, so high temps are the order of the day.
 

·
Premium Member
Joined
·
3,357 Posts
Discussion Starter · #3 ·
I was talking about viscosity, not brands...
 

·
Premium Member
Joined
·
4,012 Posts
so was i; i inadvertntly gave you the brand (so as to know what viscosity im refering to). the viscosity i "prefer" for street and drag is the race41. ive used 21 on occasion but it seems to break up way too fast, at least that was my perception.
 

·
Premium Member
Joined
·
3,357 Posts
Discussion Starter · #5 ·
I had a feeling that's what "race41" was. So what does that translate to in regular terminology?

I've been using 5W-30 for everything, but I recently had somebody trying to tell me to run 0W-30. I definitely don't want to do that, and in fact I've been considering moving to a slightly heavier oil for racing.

My car makes plenty of power for my amateur road racing needs right now (e.g. the good Mister Babel can't catch me on the straights), so I'm more interested in protection, especially given the V10's apparent proclivity for oil starvation in hard prolonged turns (thinking about 80MPH passes through the 180 at Sebring...). I certainly don't want to lose power, but I'm wondering if 5W-30 is good enough.

I'm also wondering whether anyone steps up to something heavier for day to day traffic driving in hot weather, and so on.
 

·
Premium Member
Joined
·
4,012 Posts
im no tech so here goes nothing;

race41 is "similar" in its viscosity and thermal breakdown resistance properties (whatever the fuck that means) to 10w40. without the literal viscosity. so, from what im told, a lighter oil that acts like a heavier oil with regard to protection and wear resistance but has the "quick" attributes of a lighter, or more appropriately, less viscous oil.

what I notice is clatter seems to lighten up a bit, not so noisy from under hood. car runs a bit cooler too. I also notice my wallet gets lighter easier now, LOL.

probnably doesnt matter in my case what oil i use as i change it before and after evey race and also every 2500 miles. plugs the same.
 

·
Registered
Joined
·
32 Posts
A multigrade engine oil is formulated with the "light" base oil, then a viscosity index improver is added to reach the "heavy" end. It's not quite this simple, but you start with a 10W oil and add VII to make it a 10W-40. With time, RPM, and general use, the oil gets cooked, sheared, and dirty, and the viscosity will head towards a 15W-30. The heat makes the "light" characteristic become less "light" and the RPM and shearing make the "40" characteristic fall. I say "heads toward" because the viscosity specifications are a range, not an exact number, so the oil can get slightly thicker or thinner and still be the same viscosity grade.

You might want to think of your oil selection this way: you want the least effort to pump the oil around and get it to where it needs to be, then you want it to support the bearings under the conditions you experience. So you would want a low "W" number and a high enough "second" number to prevent bearing contact. If a 5W-30 was sufficient, then a 0W-30 will be also, but have a pumping advantage. If you want thicker, then a 5W-40 will have the same pumping effort, but more bearing protection.

Synthetic diesel oils are 5W-40, and Mobil makes one called Delvac 1, Shell and Chevron Delo have them, too. Roughly same price as synthetic passenger car oils, so a "cheap" race oil.
 

·
Premium Member
Joined
·
3,357 Posts
Discussion Starter · #10 ·
Hi Tom, I didn't know you lurked in the Alley.

Why have I read that dedicated racing engines often run 20W-50? This meets your "second number" criteria which I gather is high-temp protection, but what could be the value in running such a high viscosity on the cool end of things?

Tom, do you still run that 5W-40 diesel oil for street & track? I think you told me once that it was your all-around oil choice for your Viper.
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top