I recently changed from regular oil to a Valvoline Synthetic blend and my oil pressure at idle is lower than it was. It was pretty low before and now I'm getting concerned. My question is whether or not the change is normal and whether or not the better lubricity is ok with poor oil pressure. Also, I should note that the oil pressure does increase with rpm's and is 25 lbs at 2000 rpms. Any suggestions?

MaTt

25 psi at 2000 rpm does seems pretty low.

The change from regular oil to a Synthetic will drop psi some, it's common, and safe.

but that 25 psi sounds low. I think safe spec is 20 psi at 1000 rpm idle, then 10 psi for ever 1,000 rpm above that

25 is OK, but it is rather low.

<font face="Arial,Verdana" size="2">Originally posted by Mz28att:
I recently changed from regular oil to a Valvoline Synthetic blend

MaTt</font>

Why?

Okay-everyone needs to read this link and then you will understand why synthetics are way better than conventional oils in every way-no excuse to NOT use synthetic. I would use Amsoil first, Mobil 1 second.
http://www.performanceoiltechnology.com/AutoIndustry'sBestKeptSecret.htm

[This message has been edited by gmachinz (edited January 03, 2005).]

25 psi is acceptable at 2000 rpm. Mine USED to be 15 psi at idle. You can play with your oil viscosity and most likely elevate it. If you're running 10W30 then you're not abnormal. Step it up to 10W40 or 15W40 and you SHOULD see a difference on the guage as I did.

As for switching from synthetic blend to regualar dino oil, I bet it was for $$$ reasons. Synthetic oils are superior to conventional oils thus cost a bit more. Synthetics have better flow characteristics in COLD temps, viritually will not fail within any temp your car can create, and are a lot easier on your seals and gaskets. I personally perfer Pennzoil 5W50 full sythetic because it gives you a broad range of protection. I run it in my '94 Accord with over 200K miles on it. I use 5K mile service intervals and the car doesn't use or leak a drop in that interval.

I've been in the Oil Change industry going on 12 years and I've seen it all, both going in and coming out of an engine. Brand name isn't as a big of a concern "IF" you service your vehicle accordingly. Find the best weight for your car and use whatever brand you want.

And if your engine was built tight enough to use 5W-20, Walmart sells the Motorcraft synthetic oil for the same price as the conventional oil, I think $1.44/qt.!

So even if its a band-aid type fix, what shift in weight would see an increase in idle oil pressure?

MaTt

I fully endorse synthetics, and use synthetic oil in my daily driver truck, but be careful if you're using an aftermarket camshaft. The cam I have in my Camaro specifically states DO NOT use synthetic oil, as it may, and I quote, "...lead to the eventual failure..." of the camshaft.

<font face="Arial,Verdana" size="2">Originally posted by gmachinz:
Okay-everyone needs to read this link and then you will understand why synthetics are way better than conventional oils in every way-no excuse to NOT use synthetic. I would use Amsoil first, Mobil 1 second.
http://www.performanceoiltechnology.com/AutoIndustry'sBestKeptSecret.htm

[This message has been edited by gmachinz (edited January 03, 2005).]</font>

That article seems a little biased to me.

I have never been an advocate of synthetics unless you need it for extreme conditions (and I mean extreme, like race cars). Your daily driver will still contaminate the oil wether it is synthetic or not, within a certain amount of miles, so prolonging your oil changes is not a good idea. Also, you still need to change your oil filter.

minimum 10PSI per 1000RPM is a good safe guard

<font face="Arial,Verdana" size="2">Originally posted by theflash:
I have never been an advocate of synthetics unless you need it for extreme conditions (and I mean extreme, like race cars). Your daily driver will still contaminate the oil wether it is synthetic or not, within a certain amount of miles, so prolonging your oil changes is not a good idea. Also, you still need to change your oil filter.</font>

I didn't read the article, but here's my $0.02.
This is in my daily driver - '92 LeBaron with a 3.0 V6.
Part of my commute to work and school involves going up 'the hill' out of the valley where I live. This is a 8 mile (?) hill at 6-8% grade - it's steep. The engine really doesn't like doing this climb in top gear, so I put it down into 3rd (auto) and it runs ~3250rpm up the hill.
Anyways, with standard oil, after reaching the top of the hill I would drop it back into overdrive, the RPM's would drop back down to 2250 or so, and the oil pressure would fall to about where it reads at idle (!) for the next 5 miles or so.
When I switched to Mobil 1 oil in the car, I noticed that this did not happen - oil pressure would go right to the usual cruising pressure when I shifted back into OD.
My only conclusion is that the extended high RPMs heated up the oil enough to drop the viscosity on the conventional oil, but did not bother the synth. Needless to say, I'm sold.

------------------
-'77 Camaro - 357, home-ported heads and intake, Q-jet, headers, hyper flattops, ~8.5:1, 3.42 gears, 214/224 cam, 112LSA, rear discs coming soon
-'92 LeBaron LX sedan - all family owned, great daily driver and highway cruiser. 52mm TB, rear discs swapped. 5-sp swap in the works.
-'70 Camaro - 350, 4-sp, needs work, lotsa fun
-'65 Nova - 230 I6, 3 on the tree, nothing power. HEI swap. 5sp and 4 wheel discs in the works.

Once you understand what film strength, lubricity and heat of vaporization means, there is no way to argue against the use of synthetics-in everything. Common knowledge that frictional heat robs power-no matter how small. Now, sure your engine will contaminate the oil-but it's the lack of quality oil that creates most of the "contamination" i.e. sludge, varnish deposits, metal particles that get by the filter, etc. So if you eliminate that, you're left with a motor in much better condition. It will make more power, last longer, and give you better mileage. A contributing author of the article, Dave Mann is a degreed mechanical engineer who specializes in lubrication/filtration systems. I've talked with him before about several topics including oil control. This article is a summary of what he and his team have discovered over 18+ years and while working closely with all the major NASCAR teams as well. I'd take it as lesson learned and move on whether you choose to believe fact or not. His "biased" objectives are tested examples-not just bench-talking and hot-air.

Here's my $.02. I have a 93 Cutlass Supreme with the 3.1. 212k on the original engine and tranny. I still get 30 mpg (which is better than advertised from Olds)on the highway and 0 leaks. At 150k a friend of mine was looking at buying a used car and asked me to go with him for my "mechanical expertise". I asked the salesman when the last oil change was and he stated they just changed it..key was it was coming from a salesman. I pulled the stick and took my friend to my car and pulled mine. With nearly 100k more and needing a change vs. new mine was SIGNIFICANTLY cleaner. A few months prior to this my tranny started to not go in gear until the fluid was hot (when it was cold outside). I changed the fluid and the following Spring the same thing was happening. I decided to change from synthetic blend to Mobil 1 tranny fluid and I have not had that prob again. I will not EVER use anything else. Now the mission is to see how long will it go. Instead of new cars it is a boat and making the buggy go faster.