10W40 in the 3.8 SFI???

[1BADT]

Just wondering if it is safe to run 10W40 oil in these engines? Running the heavier weight should increase oil pressure some and maybe slow down a few of the leaks in my 178K engine. The car is never raced just driven daily when it's dry outside. Or should I just stick with the 10W30 I've been running? Any opinions are greatly appreciated. Thanks

 

[Outpost]

We use 10w40 synthetic in our cars, and have been considering stepping up to 20w50 for warmer weather use. I'd be interested to hear additional opinions...

 

[TurboDave]

I run 20W50 in the summer months.

 

[Wes]

the only ppl i know running that heavy a weight oil dont run the oil coolers ... that is .. the ones up here where its generally cooler

 

[scottyb]

I heard that you don't want to use 10w-40.
Look here

I use 20w-50 year round for my high mile TR (165,000).

 

[The Radius Kid]

I live up by Niagara Falls Canada and I've run 15-50 Mobil 1 synthetic year round for 3 years now,no problems.

 

[bruce]

Been running 40W Valvoline racing for years.
When every one was having their cast roller cams fail, I went 6K miles, and just showed a trace of what was happening. With having so much warning, I was able to avoid the serious damage that lots of guys had. Pulled engine changed cams, blew out oil lines, and reinstalled. And routine clena up.

trouble with syns, is that they are sooo thin, at low temps it drains completely off the carnk so you have dry starts. No Thanks, in almost 40 years of street race car work, I've never had a problem with Valvoline 40W racing.

It's more about it being fresh then anything else. Long highway trips and oil lasts along time, racing stop light to stop light and you need to change every 3K.

Some years ago, I spent a couple weeks in Gasoline Alley, back when thye did overhauls at the track, and I don't remember an engine that wasn't runing valvoline.

 

[The Radius Kid]

Originally posted by bruce
Been running 40W Valvoline racing for years.
When every one was having their cast roller cams fail, I went 6K miles, and just showed a trace of what was happening. With having so much warning, I was able to avoid the serious damage that lots of guys had. Pulled engine changed cams, blew out oil lines, and reinstalled. And routine clena up.

trouble with syns, is that they are sooo thin, at low temps it drains completely off the carnk so you have dry starts. No Thanks, in almost 40 years of street race car work, I've never had a problem with Valvoline 40W racing.

It's more about it being fresh then anything else. Long highway trips and oil lasts along time, racing stop light to stop light and you need to change every 3K.

Some years ago, I spent a couple weeks in Gasoline Alley, back when thye did overhauls at the track, and I don't remember an engine that wasn't runing valvoline.

Now wait a minute,I understood that syn's tend to leave a film of oil on the parts[brg's,etc.] that doesn't bleed out after shutdown.I get no knock on startup,ever.
However I have seen more than one "dyno oiled" car that had knock on startup[using good filters].
However,a true 40 weight should stay in the bearings and such after shutdown due to it's high molecular weight.
How do you see this one Bruce?

 

[1BADT]

These are some great replies, Keepem coming... I Always heard that synthetics were supposed to stick to the internals better than standard oil. Or is this one of the many myths of synthetic oil? Part of the reason I want to run a heavier weight oil is when I cold start my car lately, I here ticking for a split second and am worried that I'm not getting enough oil pressure at start up. Any opinions on this would be of great help also. THANKS

 

[scottyb]

1BADT, I changed from 10w-30 to 20w-50 for the same reason among others:

1. High mileage, 165k
2. Rear main leak.
3. Valve noise on cold run.

I don't know if it has has any adverse affects, but the switch "slowed" the rear main leak to an acceptable level and stopped the valve noise altogether. I have been daily driving for 11k miles now, so far so good.

 

[Turbojorge]

10W 40 user

I was running 10W 30 earlier in the year, but I decided to switch over to 10W 40 for thr summer months. Never really had any problems with any leaks or compression. Then again, I change my oil every 1,000 miles just to keep the old and tierd 157 K mile motor clean.

I think I'm just going to stick with the 10W 40 (Pensoil) all year round since this is Florida and It will be 90* in November.

HTH

 

[GrndNatnl]

20W-50 in the summer... 10W-40 in the winter.. I'm thinking of going to Mobil 1 Synthetic 15W-50 when I have the cash flow to spend $30 bucks on changing my oil.

Anyone use synthetic blends? Like Valvoline's, or Castrol? I use the regular GTX oil in the car now.

 

[KWIKR 1]

I've seen a 5W/50W syn oil . Seems this would give you all round protection .

 

[clean86]

I would use Kendall 20 50, it is the only oil that will hold up in a fuel car as well as a alcohol car. The oil gets washed down real bad '{lots of fuil in the oil real quick} Just my 2 cents