5w-20 in Older Engine? Ford 7.5L V8

[The_Eric]

Originally Posted By: Garak
Or, as opposed to two choices about Ford's thinking, there are two things one can think about oneself. 1) Have 5w-30 and 10w-30 disappeared off the shelf and become unobtainable? 2) Have 5w-30 and 10w-30 been priced out of contention?

If the answer to those is "no," then there's no reason to bother with going lighter. The desire to switch was for fuel economy. The difference in fuel economy between a 5w-30 and a 5w-20 will not be measurable by those of us without labs and bench testing equipment.

@92saturnsl2: By the way, forget the STP garbage. It'll dilute your ZDDP content, rather than enhance it. I demonstrated the calculations ages ago in the VOA section.


Actually, he said he wanted better mileage and better starting/less load on the starter/battery.

I agree that any mileage gains would be only as the engine were warming, and hard or impossible to accurately quantify.

 

[390pi]

There was another TSB before the one about 5W20. Goes back a little further and makes 5W30 recommended on older stuff.

Motor Oil - SAE Viscosity Grade Recommendation - Service Tip
Article No.

99-8-16


PUBLICATION DATE: April 26, 1999


FORD
1989-93 Festiva
1989-94 Tempo
1989-97 Probe, Thunderbird
1989-99 Crown Victoria, Escort, Mustang, Taurus
1994-97 Aspire
1995-99 Contour
LINCOLN-MERCURY
1989-92 Mark VII
1989-94 Topaz
1989-97 Cougar
1989-99 Continental, Grand Marquis, Sable, Town Car, Tracer
1991-94 Capri
1994-98 Mark VIII
1995-99 Mystique
1999 Cougar
LIGHT TRUCK
1989-90 Bronco II
1989-96 Bronco
1989-97 Aerostar, F Super Duty
1989-99 Econoline, F-150, F-250 LD, Ranger
1991-99 Explorer
1993-99 Villager
1995-99 Windstar
1997-99 Expedition, Mountaineer
1998-99 Navigator
1999 Super Duty F Series

ISSUE Ford Motor Company now recommends SAE 5W-30 viscosity grade for servicing any Ford gasoline-powered vehicle regardless of model year.
ACTION When servicing any Ford gasoline-powered vehicle, use SAE 5W-30 viscosity grade motor oil. Refer to the following text for further details.


Both SAE 10W-30 and SAE 5W-30 viscosity grade motor oils have been recommended in the past depending on vehicle model and model year.

Tests have proven SAE 5W-30 viscosity grade motor oil provides the optimum protection and benefits for Ford gasoline engines. At both high and low ambient temperature conditions, SAE 5W-30 provides the best overall protection. It allows faster starts under cold ambient temperatures.

SAE 5W-30 also provides approximately 1/2% increase in fuel economy over SAE 10W-30.

SAE 5W-30 viscosity grade motor oils certified for gasoline engines by the American Petroleum Institute (API) should be used for all service procedures requiring replacement of the motor oil.

 

[Kuato]

Originally Posted By: Chris142
Rotella 5w40...


+1. I'm surprised it took us this long to suggest it!

 

[CurtisB]

I had a 460 4V in an old 1974 Lincoln MKIV, which I sold three years ago with 74,000 miles on an original engine/ driveline. That car leaked oil from everywhere possible, and also consumed oil. My point being switching to a 20 weight oil will without a doubt worsen oil leaks and worsen oil consumption. If I could go back in time I would have used Rotella T6 5w-40 and a Motorcraft oil filter with that old beast, and that's what I would recommend you do with yours (I owned the car for 10 years).

As far as fuel consumption goes, that thing is gonna be a glutton on gas no matter what, keep clean filters on it and keep the timing smooth that's probably the best you can do. You may get a slight improvement in fuel economy and better cold starts by rebuilding your carburetor with a rebuild kit if that is something you have time for.

 

[steve20]

Originally Posted By: Kuato
Originally Posted By: Chris142
Rotella 5w40...


+1. I'm surprised it took us this long to suggest it!


Agreed, and please skip the STP

 

[Kuato]

Originally Posted By: steve20
Originally Posted By: Kuato
Originally Posted By: Chris142
Rotella 5w40...


+1. I'm surprised it took us this long to suggest it!


Agreed, and please skip the STP


STP?

 

[Garak]

Originally Posted By: The_Eric
Actually, he said he wanted better mileage and better starting/less load on the starter/battery.

If one is really concerned about the latter, then I would recommend one go to a high VI 0w-30. Incidentally, I was using 5w-30 in Ford vehicles year round long before the TSP posted by 390pi was issued. That was the whole point of the 5w-30 grade, after all.

As I mentioned, my concern about the 5w-20 is his rather long commute. Personally, seasonal oil changes drive me nuts, so something that could be run year round would be a better option. My old Audi permitted 5w-20 in the winter. I didn't bother, though since it did consume thinner oils, and a 5w-40 or 0w-40 would work all year.

 

[92saturnsl2]

Thanks everyone for the responses. Ultimately, in the name of science, I went with 1 quart 5w-30, and 5 quarts 5w-20 QS Defy. I'll get a UOA done at the end of winter when it's changed out, it will probably have 5k or more on the oil by that time. If it shows elevated wear, that will be the last of my thin oil ambitions for this engine.

I find it interesting that ford back-spec'd the 7.5L to 5w-20, at least in the 93-97 model years. That old dinosaur of an engine never changed a whole lot-- The first 429/460 engines introduced in the 60's, aside from a switch to EFI in 1987 and changes to compression ratio remained essentially unchanged. The only thing unique about the 1993 model year 460 was a slight redesign of the cylinder head which increased power (larger intake valves is largely attributed to the power increase). It still retained the flat tappets even through the '90's. So you have to wonder why they decided on 1993 to begin the 5w-20 recommendation.

I did a lot of work on the truck over the summer, including new timing chain, rebuilt the carb, all seals (except rear main) and all ignition / maintenance items were replaced. I downsized the jets for our altitude here, and the truck runs as good as new. Plugs when pulled are a nice tan like they should be, so I don't see fuel dilution or leaks being a serious issue.

I don't know what kind of oil temps this thing sees, but it has a factory oil cooler that, AFAIK, does not have a thermostat. So it's quite likely the oil temp is not as high as something a little better regulated.

Not saying the 5w-20 is the end-all answer, but I think it's worth trying. I browsed the UOA forum and didn't see any examples of 5w-20 being harmful. But if the engine runs rough, produces elevated wear, etc. I'll be the first to admit it and post my experience for everyone to see.

 

[92saturnsl2]

Originally Posted By: Garak
My old Audi permitted 5w-20 in the winter. I didn't bother, though since it did consume thinner oils, and a 5w-40 or 0w-40 would work all year.


My only problem with 5w-40 and 0w-40 oils, is that they're no thinner than a 10w-30 or 10w-40 at most temps. Yes, in extreme cold (I forget the exact temps), they ARE thinner, but at nearly all temperatures I will see (0 - 60F) this winter, they will be always be thicker than a 5w-30 or 5w-20, sometimes considerably.

A lot of people make the mistake of judging cold temperature properties by the first xW number alone-- Go stick the same brand 0w-40 and 5w-30 in the freezer and see what pours easier when it comes out. The 5w-30 will by a long shot.

 

[turf1]

I have a 99 E-150 5.4L with 300k on it, now using 4 qts Mobil 1 0w30 and 2 qts Penzoil Platium 0w20 with a Fl820s filter. Great combo, no noise at start up and runs quiet.

 

[Garak]

Originally Posted By: 92saturnsl2
My only problem with 5w-40 and 0w-40 oils, is that they're no thinner than a 10w-30 or 10w-40 at most temps.

I know that, and that's specifically why I chose a 5w-40 and 0w-40. I didn't want thinner than a 10w-40 at operating temperatures, and I certainly didn't want thinner than a 10w-30, except in extreme cold. The German vehicles tend to call for a thicker oil in the first place.

Originally Posted By: 92saturnsl2
A lot of people make the mistake of judging cold temperature properties by the first xW number alone

I didn't make that mistake, though. We have a real winter here, and the last thing I want to do is be caught outside on one of the worst days with something with low pumpability. Instead of playing with the freezer to test pour point (which has limited relevance), look up some of Imperial Oil's videos of tests of 0w-XX HDEOs.

It's also important to note that there are some 5w-30 oils, and many 0w-30s, with very high VIs and several 5w-20s with unremarkable VIs. If I was worried about cold start and a decent VI for the vehicle in question, I'd be getting Petro-Canada Supreme Synthetic 0w-30 or its Duron 0w-30 or Mobil Delvac Elite 222 0w-30. They will all spank any 5w-20 on the planet for cold cranking (due to SAE requirements), plus they each have a very impressive VI.

As for using a UOA to seek out wear, I wish you luck. Unless it's something very, very alarming, you're going to have no baseline with which to compare.

 

[901Memphis]

Caterham blend would work well for this application. Maybe even M1 HM 5w20.

 

[Chris142]

BTW: No matter what oil you put in it all your going to see is 8mpg.

 

[jrustles]

Originally Posted By: Zaedock
You're probably going to get more fuel in the oil in winter with the carb, so I'd run a 5W30.


This.

 

[jrustles]

Originally Posted By: Garak
Mobil Delvac Elite 222 0w-30.


Formerly known as Esso XD-3 0w30. PAO based, it's good stuff.

 

[blackman777]

Originally Posted By: Ramblejam
"Approved For SAE 5W-20 Motor Oil: 1993-1998 7.5L All Vehicles" Of course, that's just an official document from Ford. What do they know, right?

Good way to sell more cars (by recommending too thin oils). I'd rather stick to the 0W for cold start and -30 for thick protection during cruising.

 

[Zaedock]

Originally Posted By: blackman777
Originally Posted By: Ramblejam
"Approved For SAE 5W-20 Motor Oil: 1993-1998 7.5L All Vehicles" Of course, that's just an official document from Ford. What do they know, right?

Good way to sell more cars (by recommending too thin oils). I'd rather stick to the 0W for cold start and -30 for thick protection during cruising.



Well, the '93 back spec is for an EFI engine vs. the '85 carb'd, so this post is irrelevant. I would bet dollars to doughnuts that 5W20 would be OK, but 5W30 is "safer" due to fuel in the winter time. "Thick" protection is relative depending on the oil temp. If his 20wt never saw < 180*F, he would be fine.

 

[Ramblejam]

Originally Posted By: Zaedock
Well, the '93 back spec is for an EFI engine vs. the '85 carb'd, so this post is irrelevant.


Familiar with the 460, I see? Hopefully you'll answer the question for us then, Zaedock. Either:

A. Ford made across the board changes in their entire light truck engine line (4.9, 5.0, 5.8, 7.5) for 1993 with negates the usage of 5w-20 in earlier models.
B. There's another reason that Ford selected 1993 as the beginning model year for a lighter engine oil.

 

[The_Eric]

Originally Posted By: blackman777
Originally Posted By: Ramblejam
"Approved For SAE 5W-20 Motor Oil: 1993-1998 7.5L All Vehicles" Of course, that's just an official document from Ford. What do they know, right?

Good way to sell more cars (by recommending too thin oils). I'd rather stick to the 0W for cold start and -30 for thick protection during cruising.



It's more than just a back spec and selling cars...


From the OP:

Quote:
The owners manual recommends practically any grade from straight 10W, all the way to 20w-50 depending on expected ambient temp. 10w-30/10w-40 are shown as the "all-season" oils, acceptable for 0F and up. 5w-20 & 5w-30 are shown as the cold weather viscosities for temps below 0, up to 60F

 

[Garak]

Originally Posted By: jrustles
Formerly known as Esso XD-3 0w30. PAO based, it's good stuff.

Yep, if one wants to go synthetic, one might as well use a grade that takes advantage of it.