I once heard that Motorcraft Synthetic Gear oil is a better choice than Mobil 1 Synthetic Gear oil. Is there any truth to this? Motorcraft Gear oil is definately more expensive.
Motorcraft SYN Gear Oil Better Than Mobil 1?
- Thread starter John With Beastly 302
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Unless someone can lab test it with comparative results, rumors will always be rumors.
Mobil1 is an excellent GL5 gear oil.
When comparing, one should mention the weight, application, PN..... plenty of Mobil and Motorcraft products.
And, depending on the product, the application is worth nothing. Manual transmissions and rear-ends usually work better with different syn gear oils.
Mobil1 is an excellent GL5 gear oil.
When comparing, one should mention the weight, application, PN..... plenty of Mobil and Motorcraft products.
And, depending on the product, the application is worth nothing. Manual transmissions and rear-ends usually work better with different syn gear oils.
A lot of people here are not big fans of Mobil 1 gear oils. I just put some M1 75W90 in my snowmonile chain case, and it looked like water it was so thin. Not a crtical application, but I prefer the Amsoil or Redline products...
if you're referring to the 75W90 synthetic axle lubricant, I e-mailed Ford for a PDS for this stuff because I was considering using it in my rear transaxle.
FWIW, I ended up using the Mobil 1. The specs are good, and it performed well on the much-bashed Amsoil gear lube test, which is about the only gear lube test I've seen. That said, the specs on the Motorcraft fluid where much better. It had a much higher 40C viscosity, roughly the same 100C (so obviously a much higher VI, like 30% higher if I remember correctly). The pour point was way lower, which makes me think it has a lot higher-quality base stock.
So, on paper it appears to be a better fluid. I couldn't really get past the price, though. A local-ish dealer sells stuff at online prices, and it was still $25.00/qt. Ouch...
FWIW, I ended up using the Mobil 1. The specs are good, and it performed well on the much-bashed Amsoil gear lube test, which is about the only gear lube test I've seen. That said, the specs on the Motorcraft fluid where much better. It had a much higher 40C viscosity, roughly the same 100C (so obviously a much higher VI, like 30% higher if I remember correctly). The pour point was way lower, which makes me think it has a lot higher-quality base stock.
So, on paper it appears to be a better fluid. I couldn't really get past the price, though. A local-ish dealer sells stuff at online prices, and it was still $25.00/qt. Ouch...
Motorcraft Synthetic 75W-140 / Mobil 1 75W-140
Specific Gravity
@ 60°F (15.6°C): 0.86 / 0.872
Flash Point, COC, °C: 190 / 207
Viscosity:
cSt @ 100°C: 25.6 / 24.4
cSt @ 40°C: ??? / 170
cSt @ -40°C: 135,000 / ???,???
Viscosity Index: 168 / 175
Pour Point, °C: -45 / -48
Specific Gravity
@ 60°F (15.6°C): 0.86 / 0.872
Flash Point, COC, °C: 190 / 207
Viscosity:
cSt @ 100°C: 25.6 / 24.4
cSt @ 40°C: ??? / 170
cSt @ -40°C: 135,000 / ???,???
Viscosity Index: 168 / 175
Pour Point, °C: -45 / -48
Trans or rear end?
MC stuff should be superior in a manual trans.
For rear ends, proper fluids from either would be very close.
MC stuff should be superior in a manual trans.
For rear ends, proper fluids from either would be very close.
Rear ends. One, a Dana 80 on a 05 F350 and the other a Ford 10.25 on a 91' F250. Is 75w90 to thin for a rear end. 8 years ago I changed the fuid on the 10.25 with 75w90 Valvoline Syn Power. I worry that using a thinner 75w90 causes more wear than a 75w140. Does it? A couple of years ago I changed the oil in the Dana 80 to Mobil 1 75w90 and then realized it called for 75w140 so I'm going to change it back and wondering what brand is a good choice.
The 75-90 manual trans fluid is the best I have heard of on paper, or have used.
Absolutely wonderful made in Germany fluid.
But I just saw your last post [which should have been in the first post].
Being in Cal, you can use the 75-140 [and can help with worn parts]. But unless you have extreme needs, this should not be necessary. A modern full synth 75-90 should be great.
Absolutely wonderful made in Germany fluid.
But I just saw your last post [which should have been in the first post].
Being in Cal, you can use the 75-140 [and can help with worn parts]. But unless you have extreme needs, this should not be necessary. A modern full synth 75-90 should be great.
Originally Posted By: mechtech2
But I just saw your last post [which should have been in the first post].
Being in Cal, you can use the 75-140 [and can help with worn parts]. But unless you have extreme needs, this should not be necessary. A modern full synth 75-90 should be great.
Then why does Ford Recommend a 75w140 on a 05 F-350 6.0 Dually Dana 80 axle?
But I just saw your last post [which should have been in the first post].
Being in Cal, you can use the 75-140 [and can help with worn parts]. But unless you have extreme needs, this should not be necessary. A modern full synth 75-90 should be great.
Then why does Ford Recommend a 75w140 on a 05 F-350 6.0 Dually Dana 80 axle?
John, most of the recommendations are based on two things; use of the truck at GVW or GCVW and the available oils in the era the truck was built. Plus fuel economy, because gear oils can add or detract from fuel economy to the tune of 1-2%.
Unless you know diff oil temps, you really can't make an educated choice outside of the OEM recommendations. You can evaluate conditions and operating environment and make a good guess, though.
In either axle, if you run light loads and seldom run heavy, gear oil temps will be low and a 75W90 will be fine. It will boost your MPG a little vs a 75W140. This will be especially true if you are a short hopper in town.
If you run heavy and/or spend a lot of time on the road and get the gear oil hot (hot being defined as at, near or over the 212F temp point used for measuring the viscosity grade), then a 110 or 140 could be in order.
Since I have used diff oil temp gauges for nearly a decade in my trucks, and in communicating with other drivers with trucks so equipped, I have some perspective on gear oil temps. Lightly used, most trucks will seldom see over 180F. If that's "it" for your truck, then running a 75W140 will result in a lot of wasted energy, because at that temp, the oil is very thick... in or near the 250 grade. And it stays that way forcing your truck to use extra fuel
If you haul or tow, especially over long distances, then you might see oil temps at 212F or higher. That's when the 140 grade comes into play.
My goal is to have the oil run at a viscosity equivalent to no less than the minimum cSt in the 90 grade, at the maximum temp the oil runs in my truck for any length of time. For my trucks, even though they tow regularly, it's for relatively short distances (field to grain elevator) and my diff temps seldom reach or exceed 200F. In that realm, 75W90 works great for me. Plus, I have a finned, high capacity cover that reduces my diff oil temps... plus the gauge is there to warn me if I get carried away.
Viscosity isn't the only protection in gear oil, don't forget. There is a bigger need for boundary lubrication in gear oil and that's why they are chock full of so many anti-wear additives. These additives provide much of the protection in gear oil and that's why it's not such a big deal to run shorter spurts at higher temps. It's those long, long runs at high temps that kill the gear oil and ultimately your rear axle.They are experimenting now with 75 and 80 grade gear oils and finding that with the right additives, they protect very well. Get on the Lubrizol website and find out more.
My overall logic is that if you tow or run heavy 5-10 percent of the time, it makes no sense to hurt yourself MPG-wise the rest of the time by running a heavier grade oil than you need.... even if that hurt is only 1-2%. If you lived in a cold climate that hit could be even more in the winter. If the oil temp exceed 212F towing for five minutes going up a hill, no biggie. It will cool back down. It's possible that you might see some overly high temps towing (which I define as over 250F) only occasionally, so you might have to take the hit in the daily driving department and use a heavier oil to preserve the axle. I contend, however, that a diff temp gauge allows you to monitor and make adjustments to the situation to keep that temp lower (see the list below). Also, a higher capacity, finned cover might be enough to maintain those lower maximum temps with a lighter oil, though it also keeps the oil cooler longer.
Assuming demonstrated overly high temps, I've crunched the numbers a couple of ways and using 1% drop of economy, it comes out somewhat cheaper to just use the heavier oil than to spend a lot of money on covers and such, but that would depend on how much hit there truly is on fuel economy and the cost of fuel. I strongly believe the diff temp gauge is a worthwhile addition for any truck that tows.
Some general things I have learned:
1) At a given load, a larger ring gear axle will run cooler than a smaller (more tooth contact to spread the load)
2) At a given load, a lower ratio (4.10. 4.56:1 etc) will run hotter than a lower (3.23-3.55:1, etc, ... more hypoid action creating more heat)
3) At the same viscosity a syn oil will run about 10 F cooler than a mineral, EXCEPT mineral oils with special additives. I used a LE oil (LE607), which was a straight 90 but one that had lots of a proprietary moly-like additive that surprised my by running as cool as a well-known syn. The Chevron ESI oils are said to exhibit similar characteristics, though I have not seen that demonstrated personally.
4) Fluid friction from an oil heavier than needed causes the oil to run hotter.
5) At any given load, the faster you go, the hotter the diff runs. Some of that is load due to windage but some comes from the diff itself... that hypoind sliding action occurring more often and heating the oil faster.
6) A higher viscosity oil than you need for the operating temp costs fuel economy.
Unless you know diff oil temps, you really can't make an educated choice outside of the OEM recommendations. You can evaluate conditions and operating environment and make a good guess, though.
In either axle, if you run light loads and seldom run heavy, gear oil temps will be low and a 75W90 will be fine. It will boost your MPG a little vs a 75W140. This will be especially true if you are a short hopper in town.
If you run heavy and/or spend a lot of time on the road and get the gear oil hot (hot being defined as at, near or over the 212F temp point used for measuring the viscosity grade), then a 110 or 140 could be in order.
Since I have used diff oil temp gauges for nearly a decade in my trucks, and in communicating with other drivers with trucks so equipped, I have some perspective on gear oil temps. Lightly used, most trucks will seldom see over 180F. If that's "it" for your truck, then running a 75W140 will result in a lot of wasted energy, because at that temp, the oil is very thick... in or near the 250 grade. And it stays that way forcing your truck to use extra fuel
If you haul or tow, especially over long distances, then you might see oil temps at 212F or higher. That's when the 140 grade comes into play.
My goal is to have the oil run at a viscosity equivalent to no less than the minimum cSt in the 90 grade, at the maximum temp the oil runs in my truck for any length of time. For my trucks, even though they tow regularly, it's for relatively short distances (field to grain elevator) and my diff temps seldom reach or exceed 200F. In that realm, 75W90 works great for me. Plus, I have a finned, high capacity cover that reduces my diff oil temps... plus the gauge is there to warn me if I get carried away.
Viscosity isn't the only protection in gear oil, don't forget. There is a bigger need for boundary lubrication in gear oil and that's why they are chock full of so many anti-wear additives. These additives provide much of the protection in gear oil and that's why it's not such a big deal to run shorter spurts at higher temps. It's those long, long runs at high temps that kill the gear oil and ultimately your rear axle.They are experimenting now with 75 and 80 grade gear oils and finding that with the right additives, they protect very well. Get on the Lubrizol website and find out more.
My overall logic is that if you tow or run heavy 5-10 percent of the time, it makes no sense to hurt yourself MPG-wise the rest of the time by running a heavier grade oil than you need.... even if that hurt is only 1-2%. If you lived in a cold climate that hit could be even more in the winter. If the oil temp exceed 212F towing for five minutes going up a hill, no biggie. It will cool back down. It's possible that you might see some overly high temps towing (which I define as over 250F) only occasionally, so you might have to take the hit in the daily driving department and use a heavier oil to preserve the axle. I contend, however, that a diff temp gauge allows you to monitor and make adjustments to the situation to keep that temp lower (see the list below). Also, a higher capacity, finned cover might be enough to maintain those lower maximum temps with a lighter oil, though it also keeps the oil cooler longer.
Assuming demonstrated overly high temps, I've crunched the numbers a couple of ways and using 1% drop of economy, it comes out somewhat cheaper to just use the heavier oil than to spend a lot of money on covers and such, but that would depend on how much hit there truly is on fuel economy and the cost of fuel. I strongly believe the diff temp gauge is a worthwhile addition for any truck that tows.
Some general things I have learned:
1) At a given load, a larger ring gear axle will run cooler than a smaller (more tooth contact to spread the load)
2) At a given load, a lower ratio (4.10. 4.56:1 etc) will run hotter than a lower (3.23-3.55:1, etc, ... more hypoid action creating more heat)
3) At the same viscosity a syn oil will run about 10 F cooler than a mineral, EXCEPT mineral oils with special additives. I used a LE oil (LE607), which was a straight 90 but one that had lots of a proprietary moly-like additive that surprised my by running as cool as a well-known syn. The Chevron ESI oils are said to exhibit similar characteristics, though I have not seen that demonstrated personally.
4) Fluid friction from an oil heavier than needed causes the oil to run hotter.
5) At any given load, the faster you go, the hotter the diff runs. Some of that is load due to windage but some comes from the diff itself... that hypoind sliding action occurring more often and heating the oil faster.
6) A higher viscosity oil than you need for the operating temp costs fuel economy.
Ford not only recommends but requires 75W-140 in many rear axles. My 05 F-350 (Ford 10.5" axle) has a tag right on one of the cover bolts that says "75W-140 SYNTHETIC ONLY". IIRC, the newer F-150s have the same requirement as well.
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The last time I used MC 75w140 was in 2006. At that time the 75w140 oil didn't come with LS additives, so comparing to M1 75w140 which has LS additives might not be a fair comparison.
I just use M1 because I prefer gear oils that already have LS additives included.
I just use M1 because I prefer gear oils that already have LS additives included.
Originally Posted By: John With Beastly 302
Originally Posted By: mechtech2
But I just saw your last post [which should have been in the first post].
Being in Cal, you can use the 75-140 [and can help with worn parts]. But unless you have extreme needs, this should not be necessary. A modern full synth 75-90 should be great.
Then why does Ford Recommend a 75w140 on a 05 F-350 6.0 Dually Dana 80 axle?
Because of worst case scenarios. Worst case can be brutal.
BTW, I did not say to avoid 75-140. Only that is is not always necessary.
Jim Allen has a Master's Degree explanation above^^.
Originally Posted By: mechtech2
But I just saw your last post [which should have been in the first post].
Being in Cal, you can use the 75-140 [and can help with worn parts]. But unless you have extreme needs, this should not be necessary. A modern full synth 75-90 should be great.
Then why does Ford Recommend a 75w140 on a 05 F-350 6.0 Dually Dana 80 axle?
Because of worst case scenarios. Worst case can be brutal.
BTW, I did not say to avoid 75-140. Only that is is not always necessary.
Jim Allen has a Master's Degree explanation above^^.
Originally Posted By: Ben99GT
Comparable
exactly, whatever is cheaper go for it. You gears wont notice the difference
Comparable
exactly, whatever is cheaper go for it. You gears wont notice the difference
M1..eehh that stuff. Get the Motorcraft It is most likely cheaper and ALMOST any gear oil is better than M1. I used it in my ranger way back and it was like water coming out and always had a lot of metal in it. I used Valvoline WB 75w-90 twice and the metal shavings in the draining fluid was dramatically less. I'm sure M1 didn't do that 7.5" any favors.
Originally Posted By: DrDusty86
M1..eehh that stuff. Get the Motorcraft It is most likely cheaper and ALMOST any gear oil is better than M1. I used it in my ranger way back and it was like water coming out and always had a lot of metal in it. I used Valvoline WB 75w-90 twice and the metal shavings in the draining fluid was dramatically less. I'm sure M1 didn't do that 7.5" any favors.
I have a hard time understanding what makes M1 gear oils not that good?
M1..eehh that stuff. Get the Motorcraft It is most likely cheaper and ALMOST any gear oil is better than M1. I used it in my ranger way back and it was like water coming out and always had a lot of metal in it. I used Valvoline WB 75w-90 twice and the metal shavings in the draining fluid was dramatically less. I'm sure M1 didn't do that 7.5" any favors.
I have a hard time understanding what makes M1 gear oils not that good?
Originally Posted By: John With Beastly 302
Originally Posted By: DrDusty86
M1..eehh that stuff. Get the Motorcraft It is most likely cheaper and ALMOST any gear oil is better than M1. I used it in my ranger way back and it was like water coming out and always had a lot of metal in it. I used Valvoline WB 75w-90 twice and the metal shavings in the draining fluid was dramatically less. I'm sure M1 didn't do that 7.5" any favors.
I have a hard time understanding what makes M1 gear oils not that good?
I agree. All the brand name gear oils in a general price range are pretty close together in terms of performance and quality. Each might have a slight edge in some place or other but they all can be depended upon to deliver good performance overall.
Originally Posted By: DrDusty86
M1..eehh that stuff. Get the Motorcraft It is most likely cheaper and ALMOST any gear oil is better than M1. I used it in my ranger way back and it was like water coming out and always had a lot of metal in it. I used Valvoline WB 75w-90 twice and the metal shavings in the draining fluid was dramatically less. I'm sure M1 didn't do that 7.5" any favors.
I have a hard time understanding what makes M1 gear oils not that good?
I agree. All the brand name gear oils in a general price range are pretty close together in terms of performance and quality. Each might have a slight edge in some place or other but they all can be depended upon to deliver good performance overall.
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Originally Posted By: DrDusty86
M1..eehh that stuff. Get the Motorcraft It is most likely cheaper and ALMOST any gear oil is better than M1. I used it in my ranger way back and it was like water coming out and always had a lot of metal in it. I used Valvoline WB 75w-90 twice and the metal shavings in the draining fluid was dramatically less. I'm sure M1 didn't do that 7.5" any favors.
I used it in my 8.8 behind my 5.0L without issue. I'm also using it in the 9.75 in my Expedition. Both of which I'm quite sure see much heavier use than your Ranger. The 7.5" was a junk diff in the first place, I've never seen a diff spit more axles at the track than the Ford and GM 7.5" units.
Your anti-Mobil agenda is getting pretty bloody old.
Any gear oil that has the same certifications/approvals is going to perform similarly. This means that the Mobil 1 gear lube is no worse (and likely no better) than its peers. It IS that simple.
M1..eehh that stuff. Get the Motorcraft It is most likely cheaper and ALMOST any gear oil is better than M1. I used it in my ranger way back and it was like water coming out and always had a lot of metal in it. I used Valvoline WB 75w-90 twice and the metal shavings in the draining fluid was dramatically less. I'm sure M1 didn't do that 7.5" any favors.
I used it in my 8.8 behind my 5.0L without issue. I'm also using it in the 9.75 in my Expedition. Both of which I'm quite sure see much heavier use than your Ranger. The 7.5" was a junk diff in the first place, I've never seen a diff spit more axles at the track than the Ford and GM 7.5" units.
Your anti-Mobil agenda is getting pretty bloody old.
Any gear oil that has the same certifications/approvals is going to perform similarly. This means that the Mobil 1 gear lube is no worse (and likely no better) than its peers. It IS that simple.
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