5w 30 /40 oil

[67chevemall]

What do you experienced truck guys think about running 5w 30 oil in your 350 blocks??
Buddy says it helps on start up in the cold mornings???
I like my 10w 30 Valvoline and think he's nuts??

He just blew his bottom end, and I think this lite oil might have helped out!

Cheers

[sneakysnake]

Up north, I think you would want to use a lower viscosity. it would be like cold pancake syrup in the mornings otherwise. Down south I use 10-40 in the winters and some times 20-50 in the summers,Its like water if you dont.

[VTKidder]

In Vermont, all I have ever run in any engine (GM 2.8 V6, 4.3 V6, 3.8 V6, 5.2 V8, 5.7 V8, Chrysler 4.2 I6, Saab 1.8) is 5W30. As said below, it does help on the cold mornings. This past winter we had 6 days in a row where it did not get above -20F Unless you're burning oil to begin with, and are concerned that a lower viscosity oil will burn or leak more, run the 5W30.

[tom hand]

At operating tempature there should be no differance between 10w30 and 5w30. 5w30 should give much better cranking in cold weather. As long as the oil was thick enough to maintain good oil pressure, it had nothing to do with his bottom end failing

[1972ChevyGuy]

Im running SAE30. I switched over from 10w-30. I have more oil psi now and it runs a little better

[73stepside]

i run 5w30 in my camaro and it has 133,000 and still running strong. by the way it is the preferred oil for that engine by gm

[casey]

I heard theres a new oil out for high mileage motors, whats that all about? just a thicker oil I presume

[mooneyes]

...the whole reason all the car companys started using 5w30 is the had to get a certain mpg out of all the vehicles they built so going to a 5w30 oil didnt gain much gas milage but just enough in every car/truck they sold to add up to alot on paper ...start up is one of the hardest things on an engine and the 5w30 is fine when an engine is new but get some miles on it and some clearence in the bearings and the 5w30 aint quite enough on start up..imo....remeber the only thing keeping your crank from grinding away at your bearing is the oil...and i just dont trust 5 weight on start up

[Class of 69]

I used the recommended 5-30 oil in one engine I owned. Course it was a POS Ford, but the crank went out at 50,000 miles! I've lived in MN all my life, and have never run anything but 10-30 in the winter since the Ford failure. I use 10-40 in the summer. I have a 89 S-10, 4.3 with 140,000 miles, and my 95 K1500, 5.7 with 112,000 miles. Neither uses oil between changes. I also use the biggest rated battery that will fit my vehicles to avoid any slow cranking from winter cold, or summer from the heat. I haven't needed a jump start in 22 years. The oil company's can quit making 5-30, as far I'm concerned.

[mooneyes]

i agree completly..i usually run 10w40 except in my 70 cause the old 305 has a pyle of miles and the crank is untouched and been in 3 different motors so i have to run straight 50 wt plus some stp...wonder how much longer the old girl will last?????...LOL

[Stocker]

I understand the arguments favoring 5W oils, but personally, I feel safer with 10W30 in the sump. If I lived where it got Gawd-awful cold in the winter, I'd use synthetic oil, which flows better when cold. Just my .02

[73stepside]

the 5w30 will flow faster than 10w30 at start up and in cold weather.

[67chevemall]

Some good debat!
Lots of info!
I'm 10w 30 Valvoline till it dries up!
Or Bush guy makes it illegal!LOL

Cheers

Any one else?

[1970 CST Short Wide]

Out here in Sunny Ca where I live it seldom gets below 40 F

I have always used straight Valvoline 30 in MY truck.

[stepn67]

Whats the difference in 10W30 and srtaight 30. I've learned alot from you guys. My wifes truck is an '03 and the owners manual recommended 5W30, but on the last oill change I used 10W30 and was a little worried about it. You guys have now put my mind at ease.

[SuperCheyenne72]

Im running SAE30. I switched over from 10w-30. I have more oil psi now and it runs a little

1972ChevyGuy... I agree with you 100%

I used to run 10w-30 Penzoil for many years. I also convinced my girlfriend to do the same in her 2000 Nissan Altima. Months later and old coot (no offense to any coots out there) strongly advised me to 1) stop using any 5 or 10 weights because they're like water and will be prone to slipping past the seals, burning off... or something like that and 2) to switch over to either Valvoline, or Castrol because they're the only oil companies that don't use tar (or the same stuff they pave our roads with as he referred to) in their oil, and why on earth would I want to put tar in my engine!?

I asked how the heck he knew I was running 10w-30 in my girlfriends car and he just exclaimed that he could "hear" it... sure enough as I listened closely... the engine had a weak "tingy" sound as it idled. I immediately changed her oil to SAE 30 Castrol and not only did her engine go noiseless... but her mileage went up an extra 2 miles to the gallon.

I was impressed and convinced... I then changed out my oil with SAE 30 Castrol and although my mileage seems about the same... I don't burn oil anymore... I used to have to pour a quart in every 2 fillups (once a month)... but now the habit of just carrying an extra quart of oil with me is just that... a habit.

Keep in mind this is all in Texas... but if ChevyGuy is in NC... then who knows?...