Since I put in this 15w 40 oil and the K&N oil filter my oil pressure always stays above 35psi even all warmed up at idle, not sying theres something wrong but if I have run 10w 30 forever in it and it ran perfectly is there anything bad about putting in thicker oil then has ever been in it, I was doing it in prep for this next Texas summer...

 

How hot does it get in Texas?

I would probably not put thicker oil in the car while its still cold out though.

When I had my stock motor I ran 5W30/10W30 even in 100F temps.

 

you should run 5w-30.It flows better,Thicker oil wont flow thru the passages as well causing poor lubrication.

 

well it gets into the 100's now its about 60-70... I also though thicker oil provided more heat resistance and a stronger oil film which is recomended for higher performance engines... I was just htinking if its used to 10 30 and I put 15 40 in it then it may not flow into all teh right places, but the oil I put in is supposed to flow like 10 30 when cold so I dunno.

 

This is a 350 Chevy small block, not a 2.0 litre Honda motor. With that being said, the only reason 5w30 is recommended is for gas mileage reasons because of CAFE. Even at that heavier oils don't affect mileage much. 20w50 never affected the mileage in my 4.3 S10 I used to have even when 5w30 was used. With a 350 having looser tolerances, 40 wt oils will protect better than the 30wts. It does give a better lubrication film, which is a plus for the LT1 because of the higher oil temps from reverse cooling. Patman, the oil guru on here has seen the best oil results (better than 10w30) from using 10w40 oil in even an LS1 with fairly low mileage. I think 15w40 is about the best choice of viscosity during the summer, because it doesn't have as many viscosity reducers as 10w40 will have and won't shear down as easily. For the winter, I would go down to a 10w30 at the lightest, and for a higher mileage LT1 10w40.

Jason

 

Patman is the guy who recomended the type of oil I got as well as the filter... thought that was right.

 

Yeah I was just parroting what Patman has said in the past. I'm not an oil expert although I have learned quite a bit on a forum he belongs to. It's at www.bobistheoilguy.com from there click on the Forums icon at the left of the screen. You'll find him as well as many other experts who make a living in the oil industry alone.

Jason

 

15w40 should be just fine in the LT1, the clearances are looser than most engines, especially once you get more miles on them. I wouldn't recommend a 15w50 or 20w50 oil, but a 40wt oil will be just fine, it's not too thick to lubricate properly at all. I'm going to be running a 50/50 mixture of Schaeffer Supreme 15w40 and 10w30 in mine this summer, to get the viscosity a bit higher and see how the oil analysis results look. I notice that the LT1 and LS1 tend to show better oil analysis results with a slightly thicker oil that is closer to a high 30 or low 40wt oil.

I'm still trying to figure out what oil I'm going to try out in the fall, and then for 2004, but I'm looking closely at running Royal Purple 5w30 in winter and their 10w40 the rest of the time, or possibly Mobil 1's 0w40, or maybe even Havoline 5w40. I like to play around and experiment with different oils and see how the oil analysis results pan out. It's very interesting stuff to me for some strange reason.

 

Yeah somehow it is for me too. The additive market seemed to spark my interest in oils I must say.

Jason

 

Oh I thought my 350 only has 4 cylinders.I guess the engineers dont know squat,I kinda suspected.If it doesnt affect milage why dont they recomend straight 50w?

 

Yeah I am on that forum too...Im 94 formula, pretty interesting stuff.

 

cool im mebanditws6 in case you didn't know

Jason

 

I have a 95 Chevy Camaro z28 LT-1 6-SP with 72500 miles on it I just wanted to know what you people think I should put in my beast and what in what time of the year would do good for me I have been using 5 bottles of Pennzoil 5w30 synthetic do yous use synthetic do you think it makes the difference does synthetic really do any good well i have used it in my car i dunno just to be safe everyone just tell me what you think and what will work good for me thats alot guys

 

Here's the best thing you can do for your motor. www.auto-rx.com Do a treatment of this, then switch to synthetic, preferably Mobil1. A 40 weight would be the best route. It's readily available around here in the 0w40 viscosity. You could use this for the winter if it gets cold where you live, and for the summer you could probably go to the 15w50 M1. I'm not sure about this. Patman might have a better idea.

Jason

 

I ALREADY IM USING synthetic I USE 5W 30 SO WHATS A GOOD ONE 4 WINTER AND WHY AND SAME WITH SUMMER