what viscosity oil is everyone running?

You do not want to use 10W40 in these engines. Or nearly any engine that's been made in the last 10 years. The "thickest" i would use is 5W30. I've been using Valvoline 5W30 and still have 75lb oil pressure at cold startup, 25-30 at idle and 40-60 at speed.

Don W

I use Motorcraft 5w30 in my 2000 GT which specified 5w30. However, there is a TSB released by Ford which authorizes use of 5w20 in the

If you're worried about hard driving in hot weather, put in a synthetic 5w30.

I am running Mobil 1 5/30 synthetic year round in New Jersey with our hot Summers and cold Winters. I am also running synthetic in the trans and rear as well. All Mobil 1 I might add.

Steve

I too use Mobil One 5w30 in my '98 GT year-round without any problems. Thinner oil can (and should be) run in newer 4.6's due to close engine tolerances and valvetrain lubrication requirements at startup.

As for 10w40, I wouldn't EVEN use it in my beater. Many engines during the

Using thicker oils will cause flow problems, especially at startup when it is needed most. Don't try to outwit Ford's engineers. Use exactly what they spec for that specific engine. They've spec'd a specific viscosity lubricant for a reason. If you want to go the extra mile, use Mobil One synthetic; it keeps internals squeaky-clean, lubricates exceptionally well, and dissipates internal heat better than petroleum. I won't use anything else in any of my cars.

JD Adams opined in news: snipped-for-privacy@4ax.com:

But it wasnt the "40" part that did it, it was the cheap viscosity adders. There was little room left for the Lubricant parts, as I read the story.

I dont know that the CURRENT 10w40 is as bad... but it left a sour "taste" in a lot of minds... including mine

ANd I dont really thnk that you'd hurt a new engine with Mobil 1 5w30. Though I'd wait till the warranty wasnt a question anyway. These warranty decisions are all made by ribbon clerks.

Quaker State 10W30..

climate....

Ford sells their Motorcraft 5W-20 "synthetic blend"... I just bought a case today... cost about $32... that's about $2.60 per quart, not cheap. Is there a cheaper source for this oil? I went to a few auto stores, no one had it. I suspect that Mobil 1 is even more expensive, or...? I have used Quaker State 5W-30 in all my other late model cars... but now with the Stang and the 5W-20 spec, I guess I will stick to Motorcraft for now... that's pretty thin stuff, I hope it can handle severe bearing side loads... after all, the 4.6 SOHC and DOHC are performance engines destined for drivers that will put some severe use on them. Lots of wide open throttle use, heavy loads, high rpms, etc are really going to put the oil to the test. I'd agree that it is the wisest choice to follow Ford's recommendations, but I do hope that the 20 weight will keep things protected under severe use. I can picture climbing a steep mountain at a spirited pace, 3/4 throttle or more, in 95+ degree heat, with just that 20 weight oil holding things a few thousandths of an inch away from destruction.

I prefer Mobil 1, 5W30 or amsoil 0W30. That's what I use in all my vehicles. The 5W20 is realy an administrative decision by ford. All auto makers are going there to lower their total gas consumption...A good synthetic is always a good idea...

Serge

climate....

at 09 Sep 2003, Serge [ snipped-for-privacy@hotmaill.com] wrote in news:SLk7b.3598$ snipped-for-privacy@news20.bellglobal.com:

So in an engine that can run but 5W20 and 5W30 what would be best to use? Considering central Fla location and Mobil 1 as oil of choice.

I live here in Central Florida too. The 5W-20 gained Ford (and Honda) a little more for MPG. The engines haven't changed from the "old" 5W-30 spec. If people are concerned about running the engine a little harder, go with the 5W-30 for a little more protection, especially with a Group IV Synthetic, like Mobil 1 and most of Amsoil line. The Amsoil XL-7500 line (which does have a 5W-20) is a good oil, but it is a Group III Synthetic, which has a petroleum base stock. From what I've been told, ALL synthetics out there have gone the route of the Group III oils because it's cheaper to make and more profit for the oil manufacturer. Syntec started this type of oil a few years ago. Group IV Synthetics still follow the original thought of a synthetic and are still proving to be more durable with their PAO base stock. If you don't run your engine hard, do normal driving, the Group III oils are a good choice, especially over the Group II regular dino-oils. If you want more, look to the Group IV oils. I use Amsoil Series 2000 0W-30 and go with the extended drain intervals. Also installed a bypass filtration system last year. I went 20K the year before on this oil before putting the bypass filter on. Oil analysis came back that the oil was still good. I just sent a sample off for this year, with 23K on this oil sample. I should have the results back in a week or so. DO NOT try this with a Group III or less oil, and even Mobil will not warrant their oil for this length of time anymore because they do not have the additive package anymore (plus the get more money if you change more often). Amsoil does. As to where in Central Florida has the deals on Mobil 1, I hear Walmart sometimes has good sales on it. Contact me if you are interested in Amsoil.

Run exactly what the owners manual calls for.

Patrick (living in northwest Florida) '93 Cobra '83 LTD

Agreed; the polymer viscosity improvers were the problem; they broke down quickly, leaving the engine unprotected.

I went ahead and switched to synthetic at 3000 miles, since I didn't plan to make use of Ford's warranty program anyway. Never had a problem, in fact, I think it runs better now than when it was new.

-JD

_________________________________ JD's Locally-Famous Mustang Page: http://207.13.104.8/users/jdadams

climate....

at 09 Sep 2003, Patrick [ snipped-for-privacy@aol.com] wrote in news: snipped-for-privacy@posting.google.com:

That's my problem, I don't have the one for a 98 V6 engine as my Mustang is a 95 but had to have the engine swapped a while back.

Anybody in here with a 98 V6 able to tell me what the manual states to use for engine oil?

The manual for my '98 calls for 5w30 in both V-8s and the 6's.

-JD

_________________________________ JD's Locally-Famous Mustang Page: http://207.13.104.8/users/jdadams

at 10 Sep 2003, JD Adams [ snipped-for-privacy@Promedia.Net] wrote in news: snipped-for-privacy@4ax.com:

Thanks JD, in that case I'll stay with 5W30. Motorcraft.com suggests using Motorcraft 5W20 but since I'm in Fla I believe 5W30 will do me more good and I doubt the MPG gain aachieved with using 5W20 instead outweighs that.

My last oil change I tried 5W-30W Royal Purple in my 90 GT. Now it only has