gorms

I've been running regular 15w40 forever until last fall, then I switched to 5w40 synthetic for cold starts. It's been great but I've got a feeling it's getting a little thin in the heat. Going to be doing some towing this summer, and I can't find the temp. chart for 5w40. Is it ok to tow when its in the 90's with the a/c on running 5w40? If not who sells a synthetic 15w40 that's less then $50/gal? I'd like to run synthetics from now on based on the last few months.

I was having a problem with the throttle sticking a bit (raised idle) when the truck got to working a bit, with the oil that's been in since last fall (about 8k mi). I thought it was just the throttle shaft bushings, so I made new ones. They work fine but the idle was still sticking when it got hot. Added some lucas "oil stabilizer"/thickener and it hasn't happened since. Leakage/burning of oil has been down in general with the 5w40 which I thought was weird.

HMX-1

What about using Valvoline Premium Blue?

I use it exclusively in both my diesels and my kid's '04 1500 with the 3.7L motor, and have had no issues with it while towing my Keystone Energy 260FS or my Can-Am Commander 800XT.

I get it with an oil change deal at my local dealership, 3 oils changes and tire rotations for $180.



-Kris

Fiftygrit

Your fine, in the hot weather it is the 40 viscosity thats doing the work, in the cold its the 5 or 15 at start up.

oliver foster

I have used the Valvoline Premium Blue before, about 22-25$ a gallon last time I saw it.
I use it in the winter when the synthetic oil is better for cold starts since I see -30 F here in the winter.

ronnie

40 is the viscosity normally at 100C, so 40 is 40 is 40. 5 is the cold viscosity. This should be around 14 centistrokes

BILTIT

I run 5w40 year round. I don't tow alot but when i do its about 12k.

We rarely see the 90's though, 70-80s is more common.

gorms

Decided to just top it off and run it. Has been running good, it's definetly finicky when it gets down to the bottom of the normal levl on the dipstick though (leaks). Put almost 1k miles on over the long weekend, towed in the mountains at 80-90 degrees and it never missed a beat.

Mike L

Hey Gorms - good choice to run with it. I run 5w-40 year round and tow what I deem "heavy" in cold and very warm climates (90ish). I have not had any issues or concerns although I do change oil more frequently than the collective here seem to.

Cheers!

Mike