Builds Project Pikachu: 1977 FJ40 (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

cbmontgo said:
I tend to agree, and certainly for vehicles that are parked outside. My saving grace here is that the 40 is always parked in an insulated building at night, so the block usually sits between 30 and 40 degrees in the Winter. I'm on the fence with whether to go heavier next oil change.
View attachment 2914190
Click to expand...

I'm going to go with Mobil 1 5w-30 next oil change based on the findings of the above info I read and the fact that so many vehicles recommend that oil. It's pretty cold here in Bend 10w-40 was too viscous I believe. I changed to 10w-30 at my last change and it seems to run smoother when cold.
 
@cbmontgo, Here in the PNW it's regularly below freezing in the winter, and occasionally down to the low 20's. Summer gets warm, but mornings are still chilly (50's) for much of the year. I daily drive my 40 and cold-start it every morning. I've experimented with various oil weights, studied the OEM charts, read the forums, and generally just spent way too much time thinking about it. My 40 also has a Cat, so thats another variable, which I don't want to destroy with super high concentrations of zinc. Although many well-credentialed folks on this forum run heavy oil weights, I have found that full synthetic 10W30 is the best overall weight for this climate. (The PO of my truck ran conventional 10W40 since the day he brought it home from the dealer.) I burn very little oil between changes, and my cylinder walls and cam still have a stellar finish still. The original 2F has about 170K with no rebuilds in its history. There is a noticeable difference when trying to cold-start a 15W40 oil when ambient temps are anywhere near the freezing mark in my climate. The heavier weight just drags and protests until it gets fully warm, which takes longer. It feels like the battery and starter are working a lot harder. Just my experience, hope that helps.
 
AntFarm said:
@cbmontgo, Here in the PNW it's regularly below freezing in the winter, and occasionally down to the low 20's. Summer gets warm, but mornings are still chilly (50's) for much of the year. I daily drive my 40 and cold-start it every morning. I've experimented with various oil weights, studied the OEM charts, read the forums, and generally just spent way too much time thinking about it. My 40 also has a Cat, so thats another variable, which I don't want to destroy with super high concentrations of zinc. Although many well-credentialed folks on this forum run heavy oil weights, I have found that full synthetic 10W30 is the best overall weight for this climate. (The PO of my truck ran conventional 10W40 since the day he brought it home from the dealer.) I burn very little oil between changes, and my cylinder walls and cam still have a stellar finish still. The original 2F has about 170K with no rebuilds in its history. There is a noticeable difference when trying to cold-start a 15W40 oil when ambient temps are anywhere near the freezing mark in my climate. The heavier weight just drags and protests until it gets fully warm, which takes longer. It feels like the battery and starter are working a lot harder. Just my experience, hope that helps.
Click to expand...
That does help, thanks. I ran 10W-30 in mine for a while as well when I lived in Texas. The 15/40 is some heavy stuff for a cold climate.
 
77CruiserDog said:
Beautiful picture and that's damn chilly! Funny timing as I was just reading this article about engine oils... 540 RAT - Tech Facts, NOT Myths - https://540ratblog.wordpress.com/ Based on his findings I think I'll be making a change to the oil I use and no longer using the Lucas zinc additive... that I literally poured in today. HA!
Click to expand...

This thread has be second-guessing myself... I'm reading the link you've provided.
I currently run 20W-50... have since I've owned my 40. I actually use it in my FJ75's 3F as well.
Granted I live in Phoenix and was formerly in the Middle East... coldest nights in the winter might get a tad below 40-degrees F.
 
Honger said:
This thread has be second-guessing myself... I'm reading the link you've provided.
I currently run 20W-50... have since I've owned my 40. I actually use it in my FJ75's 3F as well.
Granted I live in Phoenix and was formerly in the Middle East... coldest nights in the winter might get a tad below 40-degrees F.
Click to expand...
Yeah me too! At the top of that incredibly difficult to read thread, his credentials clearly outweigh any circumstantial knowledge I have. I know I'll stop using zinc additive based on what he shared. I'll also be trying Mobil 1 5w-30 to see how it runs. My switch here in a VERY cold Bend Oregon from 15w-40 to 10w-30 netted real results of warming up faster and starting easier. Oil pressure didn't change, nor did anything else. Really it was just the warm up and first 10 minutes of driving that improved.
 
For a cold climate you want a lower first number but with older engines you want a higher second number.
A 5w40 would be a good compromise.
 
There is a really good piece written in that "motor oil engineering, tech facts not myths" specifically regarding cold temps and cold engines.... however because his article is so hard to search and read I've copied and pasted what you can "ctrl-f" search for. "23. Multi-viscosity motor oils are not exactly what some people think"

Very interesting information. I'll be running Mobil 1 5w-30 in both of my 2F engines without any zinc additive based on his research. I guess time will tell but in his reasearch he finds that any weight of oil over 30 is too thick for proper lubrication which in turn causes higher than normal oil temps due to the slower flow rate of thicker oil. It's a horrible read because of the format but the info sure is compelling. Sorry for hijacking the thread here hopefully some of this info is helpful.
 
Last edited:
Interesting approach but remember the larger tolerances in these older engines combined with the capacity of the oil pump can cause a lower oil pressure when hot. There has to be a certain resistance for the oil pump to build up enough pressure. At the time these engines where developed there was no such thing as a synthetic oils for road vehicles. These engines are designed fo be Used with thicker oil.
 
waiting for time said:
Interesting approach but remember the larger tolerances in these older engines combined with the capacity of the oil pump can cause a lower oil pressure when hot. There has to be a certain resistance for the oil pump to build up enough pressure. At the time these engines where developed there was no such thing as a synthetic oils for road vehicles. These engines are designed fo be Used with thicker oil.
Click to expand...
I forget where in that massive collection of info, but he does mention to use conventional oil for older flat tappet engines.
 
So I reached out to him last night and he already responded this morning. He reccomends the Quaker State Full Synthetic 5w-30 for our engines. He mentions that thicker oils can sometimes reduce consumptions and leaks However, based on his tests for wear protection, he still reccomends Quaker State Full Synthetic in a 5w-30 flavor. I'll be switching in my next oil change.
 
77CruiserDog said:
So I reached out to him last night and he already responded this morning. He reccomends the Quaker State Full Synthetic 5w-30 for our engines. He mentions that thicker oils can sometimes reduce consumptions and leaks However, based on his tests for wear protection, he still reccomends Quaker State Full Synthetic in a 5w-30 flavor. I'll be switching in my next oil change.
Click to expand...


I was using Rotella T4 in my13BT. I switched to the T5 semi-blend and it was alright. I then decided to try a full synthetic Delo and my timing cover started leaking right away. :mad: The timing cover is a real pain to remove and reseal on the 13BT so I quick changed the oil after like 1000 miles and switched back to regular Rotella T4. Leak stopped.:hmm: Enough proof for me even though I run synthetic in a few of my other newer engines.
 
FJBen said:
I was using Rotella T4 in my13BT. I switched to the T5 semi-blend and it was alright. I then decided to try a full synthetic Delo and my timing cover started leaking right away. :mad: The timing cover is a real pain to remove and reseal on the 13BT so I quick changed the oil after like 1000 miles and switched back to regular Rotella T4. Leak stopped.:hmm: Enough proof for me even though I run synthetic in a few of my other newer engines.
Click to expand...

They always seem to pick up a drip or 2 when you switch from conventional to synthetic.
 
Ran Pikachu into town today to pick up brake pads and calipers for the ‘76 front axle overhaul. While cruising down Highway 24 with the 2F purring, I started thinking about how much I’m looking forward to camping season 2022. Thinking about a few new areas to hit. So many options. Wyoming, Utah, Montana, New Mexico, or just explore Colorado some more. Hmm.

Anyway, it sure doesn’t get any better than summer trip planning by the fire with a snowstorm rolling in. Life is good.
FCA89607-C4DD-41E7-A4AA-2E68C864FB48.jpeg
 
You must log in or register to reply here.

Similar threads

Ztrx
1977 FJ40
Replies
5
Views
302
EWheeler
EWheeler
Flipadelphia303
Into - 1977 FJ40
Replies
3
Views
1K
Flipadelphia303
Flipadelphia303
bru77fj40
1977 FJ40 Colorado Field Find!
Replies
17
Views
1K
Ackcruisers
Ackcruisers
77ToyFJ40
1977 fj40 fan belt
Replies
1
Views
560
charliemeyer007
charliemeyer007

Users who are viewing this thread

Total: 2 (members: 0, guests: 2)

Share this page

Back
Top Bottom