300 Inline 6 Oil Recommendation

Messages
207
Location
WA
They didn't have problems surviving tremendous abuse with the oils available back when that motor was built, so I wouldn't be too particular on the exact oil now with all the improvements that have been made in them.

I used whatever oil was around for cheap in mine and it never complained.

Pick one and drive it.
 

GimpyHSHS

Thread starter
Messages
16
I had one in a 1980 F150, and it ran about 100,000 before trade in. No issues.
My friend had one that wore out the timing gear at 300,000 miles (plastic teeth) so replaced that, sold it to another friend that put another 200,000 on it, no rebuild!
I think they used this engine in UPS trucks at one time. No guess on how many miles THEY would put on them!

What I'd like to know is this: Did all that work and money improve the power much? I always wanted more power when I had mine.

It does have waaay more get-up than it did before. At the end of the day, it's still a 300 I6, of course. I'm never gonna waste money putting it on a dyno lol, so I couldn't tell you what it makes or anything.

I had the option of going the 460 route, but decided against it. Now I have a 351w block, rods, crank, good heads, etc, laying around, so I wish I had known the Mustang would need an engine before I did all that. I may have gone that route.
 
Messages
35,943
Location
NY
I am running Delo 5w40 XSP in my 88 E-150 with the 4.9L engine. Mobil 1 TDT 5w40 is another good choice, as is Mobil 1 0W40. A little extra ZDDP is a good idea as well, that info came under advisement of a well respected Bitog buddy, and an engine re-builder. hide
 
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Messages
2,206
Location
Muncie, Indiana
I am running Delo 5w40 XSP in my 88 E-150 with the 4.9L engine. Mobil 1 TDT 5w40 is another good choice, as is Mobil 1 0W40. A little extra ZDDP is a good idea as well, that info came under advisement of a well respected Bitog buddy, and an engine re-builder. hide
Delvac ESP 5W40 would probably be a good choice too, Napa still has it on sale for $20/gal, but it looks like the Delvac rebate just ended at the end of last month, but I think they do the rebate program on Delvac twice a year in the spring and again towards the fall, TDT is now part of the Delvac rebates.
 
Messages
172
Location
VA
My dad used to have an 83 f100 stepside w/ 300 & 3 on the tree, then upgraded to an 87 that had the 300 & 3 speed w/ OD which was probably one of the worst transmissions they put in a truck for the gearing. I think you would be fine with most any 5w30 or 10w30 but I know a lot of people use Rotella in those old 6 cylinders. I used to have a 95 flareside 4wd 300 w/ 5 speed and used M1 in it, most likely either 5w30 or 10w30 whichever was on hand at the time.

You can get Rotella in 5w40, 10w30, 15w40, same with Chevron Delo which tends to be a lil cheaper but also a good oil.
 
Messages
5,618
Location
Ohio
I had one in a 1980 F150, and it ran about 100,000 before trade in. No issues.
My friend had one that wore out the timing gear at 300,000 miles (plastic teeth) so replaced that, sold it to another friend that put another 200,000 on it, no rebuild!
I think they used this engine in UPS trucks at one time. No guess on how many miles THEY would put on them!

What I'd like to know is this: Did all that work and money improve the power much? I always wanted more power when I had mine.
That's probably the only weak link with a 300 is the plastic teeth on the cam gear but look how far they go before failing.
 
Messages
2,507
Location
South Carolina
You are going to tow a car hauler with a Mustang with an F100? And a bumper hitch? You are much braver than me!

Your 300ci originally used 10w-30 but an early 90's Ford TSB allowed 5w-30. Synthetic is fine and no extra ZDDP required (even with the mild cam upgrade).

Later, again, a Ford TSB recommended 5w-20 for the 300 but the TSB didn't go far back enough to cover your F100. My '93 has used everything from 10w-30, 5w-30, 10w-40 and 0/5w-20 and practically every synthetic oil on WalMart's shelves and with over 255k miles It doesn't seem to care just as long as there is oil in the pan.

Just pick a synthetic 10 or 5w-30 oil and it will be fine (comparing oils of 1983!). My choice would be 5w-30. I've setteled on WalMart SuperTech synthetic 5w-20 for mine.

The 300 is a torque monster and I think it will tow your car hauler better than the small block Ford V8's. Mine is the newer SPFI with the split exhaust manifold and it scoots down the road very well! The 460 would do a great job but won't pass any gas stations.
 
Messages
172
Location
VA
I could be wrong but I believe the early 80's f100's were still using the 9" in them but I know his 87 and my 95 they went to the 8.8" his 83 had some form of posi or limited slip as it used to spin both tires in the snow but I guess the clutches wore out and then it became a one wheel wonder. I wouldn't worry so much about towing with it but would worry about the suspension and brakes but the rear end itself can definitely take it.
 
Messages
1,448
Location
PEARL River la
Owned a 84 F100 with this engine as well as ran heavy equipment with the 300 and this engine is bulletproof. Ran high rpms for hours in equipment but truck was slow. I had 3 on the tree and torque was unbelievable but must stay in 1st for thick mud with 2nd on occasion. I even had it overloaded more than once and had to shift to second to keep momentum up a bridge. It is an engine that requires your attention to keep in torque band. I would tow only with a weight distribution hitch on that truck. Engine will take abuse along with truck just requires your undivided attention. Miss mine.
 
Messages
172
Location
VA
This is the one I had, was a good truck but had a lot of rust underneath where the undercoating was falling off and exposing it, also the oil pan was on it's way rusting through. I've read the black pans were notorious basically rusting from the inside out but the grey ones didn't seem to have that problem. This thing was a beast and would pull anything I ever wanted too. If I had kept it I had plans to convert to the ZF transmission and obviously replace the oil pan. To really take advantage of the inline 6 you need to have a manual transmission, I've never even driven one with an auto but I've heard that it's not a very good combination to have. My dad's 83 was basically the same truck other it being 2wd and the earlier body style.
1995 Ford F150_2.jpg
 
Messages
992
Location
Florida
IMO the Comp 268 is a big enough cam that would appreciate some extra zinc. Pretty much any flavor of HDEO 15w40 would do the trick and be good for towing as well.
 
Messages
2,841
Location
Caldwell Idaho
5W-40 for year round use. I had a 79 F150 that went 350,000 miles running M1,Amsoil and Redline oils at ones a year oil change intervals . Normal compression and oil pressure at 350,000. One of my favorite engines.
 
Messages
1,015
Location
Alberta
Had an 88 250 club wagon with the 300. 3 speed transmission and 4.10 rear end made any speed over 60mph a screaming frenzy. Had a buddy replace the timing gears with steel ones at 100k miles.
 
Messages
15,185
Location
Canada
I think the mix you put in it is a good one, going forward I would stick with some kind of a 40 weight - 15w-40, 5W-40, 0W-40, whatever works for the temps you are in.
 
Messages
356
Location
Cypress, Texas
if rebuilt well you could get 300k on a regular 30 grade with supertech syn but there are much better options that hardly cost more. I have over 300k on my 05 and thats considering it had worse oil in total than yours will have in it starting now. I'd use a good euro grade like QS euro 5w-40. On the thinner side of a 40 but its cheap yet amazing and in a NA non gdi engine i wouldn't be afraid to do 10k with a good Euro. I did 10k intervals with supertech syn in my 03 and 05 since they rack up miles fast and need a change typically in a half year or a bit more and I've had no issues. recently switched out to delvac for a short time but then QS euro because i wanted a thicker oil since of a quart being burned every 3-4k on both and it went down a bit. ill probably do 13k intervals on this oil. A quart overfill and by the end it should be 1-1.5 quarts low.
 
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