It was a 6.0. I no longer own the truck and miss it severely. I thought I would save money by trading it for a 3v 4.6 Explorer 4x4, but was very wrong. The Superduty got 20 mpg on the highway, ran a 13.9 at Moroso Motorsports Park, and weighed in at 7,250 on their scales. I only used fuel from the local Pilot truck stop and used PowerService fuel additive in every tank.

I have sent in samples from a Taurus SHO, Sentra SER specV, Mercury Grand Marquis, the Superduty, and my current 5.4 F150 and all showed enough fuel dilution by 5,000 miles for me to make that my oil change interval. It's not an absolute by any measure, just an educated guess. Earlier would be better, but I'm trying to balance cost with need.

All showed they could go longer, but not without extreme change in viscosity.

I used Mobil 1 for many, many years until they changed from being a true PAO synthetic (they lost a lawsuit to Castrol over the matter). I then switched to Redline despite the cost. I now use Castrol Syntech Edge Titanium. I'm not 100% sure, but my limited research leads me to believe it is an actual PAO based sythetic. If I see proof otherwise, I will switch to Amsoil.

 

Especially the pump gas AFRs under a healthy amount of boost.

Last winter when I turned the Meth off I was dipping into the mid 10:1AFR range so I could get away with 28-30psi boost.

That'll dilute the oil in a hurry.

 

Biggest difference between the 2 is the molecules are all the same size in a synthetic, different sizes in dino oil, therefore, syn. should offer better protection.

 

Mobil 1 has been my "go to oil" since around 1990. I was very saddened by their decision to change the formula after they lost the lawsuit to Castrol. They used to list 100% PAO basestock in their literature, but no longer do. I think they changed the formula around 2001, but I'm not sure. Regardless, at this point, Mobil 1 is not what I would consider a true synthetic.

 

Ahh I see. Yea, I love diesels. I had a 6BT with a ton of fuel and "twins"

13.9 1/4 and 7250lbs is some serious power. The rough math gives me somewhere around 530rwhp/950rwtq. What fuel mods?

That's a pretty good sample pool you've got there! Shame you had to trade the PS6.0 for that sad 4.6L

I use Brad Penn, Redline, and Shell Rotella depending on what motor and what I'm doing with it.

 

I did not want to mention names but M1 got it on the frequent questions if you want to look. I think its caused by E10 and turbo running rich. That is why I said gasoline type and octane is so important. EGR also has a lot to do with the engine running hot. Carbon has a high octane rating and most of it is consumed in tubing clogging the valve. That is why regular cars run rich. CO is re entered to the engine and if there is enough O2 it forms Co2 which is the preferred emission which plants take in but the EPA is trying to limit.


http://www.mobiloil.com/USA-English/...n_Mobil_1.aspx

 

Well, that is a difference the particle size is more consistent, I wouldn't call it the biggest however.

It's a complicated subject which I went into in great detail in a couple of threads in the past only to have next to no one understand and then ignore because they have already made up their minds.

God help them if they tried to understand the Stribeck curve.

 

I think those sound like vehicles that would see "severe" use most, if not all the time (maybe not as much on the Merc).

 

Yeah, we miss that truck. It was a LOT of fun. Granted the 13.9 came with a 1.8 short time thanks to locked hubs but it made good power.

The Explorer was extremely comfortable and ran a 15.9. Much slower than the Superduty, but it did it with comfort.

My daily driver is now a 2008 F150 Supercrew 5.4 with 3.73's, CAI, and programmer. Yes, the mighty has truly fallen This truck is comfortable, but is a total pig. No power AND poor fuel economy. Tows my car trailer just fine, but honestly no better than the Explorer did and FAR from what the Superduty was capable of.

What oil would you suggest for the Fit and F150? They are all close enough to the same cost once you consider total vehicle expense.

 

Me too, I still use it in the van but not in the Civics. I used it in the FIT and had no real problems and changed it every 6000 miles. I think the lack of additives is the problem and not the base stocks. PAOs take time to form the barrier that is needed for bearings but have good lubrication for slide protection for the rockers. I think its a combination of a lot of things. Fuel, temp,lack of additives and driving style.


Did you ever see this http://neptune.spacebears.com/cars/s.../oil-life.html ?

 

I'm proud to say that every vehicle in my family sees "extreme use." My Mom's first ticket was when she was 16 for doing a burnout in her Mustang. I'm happy to say that I'm carrying on that tradition That being said, we take care of our vehicles and have very few problems.

 

So then this question... if any of your vehicles saw less extreme use... would the oils last longer?

 

I truly don't think so. The GM was a highway car and the specV was mostly a show car. Fuel dilution is more a function of miles and being driven when cold more than anything. If you fire up your car and drive less than 10 miles or so to work, you are diluting your oil with fuel more than someone who drives long distance.

Don't get me wrong here. I'm sure an average Fit will last an average time using the Honda recommended oil change interval with the average oil. If that is your goal, go for it. I just expect more.

I see plenty of posts on line from tons of people compaining about oil consumption from their late model cars. I'm not, nor have I ever been one of them, but I use good oil and change it often.

 

The Fit is happy with any of the following...
0w20 (what I have been using for a couple years now)
0w30
5w20
5w30
10w30

Colder climates obviously you want the 5w and 0w to get a film going on the bearing races as fast as possible. I am installing a remote oil temp and oil pressure sending unit this spring as that will give me better data. You want 10psi increase for every 1000rpm.

For the 4.6 since you tow with it I would go with a 5w30, 10w30, or 5w40.

I will be switching the Fit over to 5w40 once the turbos are on, and its what I currently run in the race car for street/strip duty. I am particular to Shell Rotella T6 5w40, and then use additives. But really anything in that category will be sufficient.

Even then, different motors like different weights when warm.

 

The lowest acceptable cold weight is important because you need the pressure to pry the crank off the bearings and form the wedge on the leading side as the crank crawls up the leading side of the bearing..

Which is why most gas engines need roughly 10psi per 1000rpm

Usually with a minimum of 15psi at idle and often no more than 100psi at redline.

I also had to match my oil to not only my engines needs but to the journal bearing center section of the big honkin diesel turbo hanging off the manifold.

Which is fed from the head instead of the oil filter housing because of its own requirements per Borg Warner.

It needs no more than 80psi on cold start, 15 psi at idle, 30psi minimum under load and no more than 70psi under full boost so it doesnt blow by the seals.

Now I've switched turbos on the race car and need to dial it in all over again.

Now for the Fit I have to match the oil to the engine, the small Mitsu turbo and the bigger Garrett that will be feeding it and they both have their own ideal operating ranges. So I need to bust out some gauges and various sized lines, filters and restrictors to make everything cooperate.

Oil pressure can even affect spool!

Oil selection becomes incredibly complex very fast when you get down to what the engineers are trying to accomplish with one fluid.

 

Some thing I typed up a while back that might make good food for thought:

You want an example of how a simple change in oil can create a significant difference in fuel economy and power (which are both related by the way, one often follows the other)

The following was originally intended for one of my boosted gas 2.0L's

There is something called Bearing Operating Condition(BOC) which can be one of 3 states, but you really only want it operating in the 3rd state, fully developed hydrodynamic lubrication. Which correlates to a BOC of 35+. The formula to find BOC is as follows:

BOC = Viscosity x RPM x Diameter x K / Unit Load



Viscosity is in units of absolute viscosity. "K" is a value to convert RPM and Diameter into surface speed. Unit Load is the applied force divided by the projected area of the bearing (the insert width times the journal diameter).

First, viscosity. I can't find absolute/dynamic viscosity numbers for various grades of motor oil, so I took the Kinematic Viscosity of 10w30 (dino) motor oil at 100*C and multiplied it by it's specific gravity. This should give me the Dynamic Viscosity.

Second is the value "K". To find surface speed you multiply circumference by RPM. So Diameter x Pi x RPM = Surface speed, therefore K = Pi Right?

Lastly, unit load. I used 12,000 lbs of force, but this is relative to motoGP/Formula1 type engines, not boosted 4cylinders. I know our engine's see a BMEP nearly twice that of a formula 1 car, so it is a conservative place to start.

I also had no bearings out of the motor to measure their width, so I just put a caliper on the main cap and eyeballed it. I came up with an area of 1.425, so a load value of 8421.

Put it all together, 8.4 x 9500 x 2.245 x 3.1415 / 8421 = 66

The optimal range between 35 and 50 so we are well out of that range.

From here we can use the Stribeck Curve to find our friction coefficient, which I found to be .0057

So with an applied load of 12,000lbs, that gives us a friction load of 68.4 lbs. The diameter of the journal used is 2.245, so 1.1225 x 68.4 = 76.7 in/lbs or 6.39 lb/ft.

At 9500 this equates to 11.56 hp per main bearing.


That is 8600 watts of energy wasted per bearing, and that is only for the 5 main bearings!

That is not accounting for all the rockers, cam journals, cylinder bore contact patches, rod journals or wrist pins. Or the oil pump its self.

 

Thinking about it, this makes a lot of sense... more fuel = more load, etc.

Thanks for pointing that out everybody

 

So, I forget where, but I think it was DSM and SB that brought up oil change interval based, not on miles, but on fuel usage.

So that begs the question of... how much fuel usage is the indication for one cycle?

During break-in, my MM went to 6k miles before hitting 0% and I had roughly 30 mpg at the time, meaning I used about 200 gallons of gas.

On my road trip, one oil change cycle went 7.75k miles when it hit 40% (first 1k was before trip and dropped to 80%), before i changed the oil, so it could've gone close to 15k (if you assume the remaining 40% was more of the same on the road trip). But because my MPG was only about 34/35... the fuel usage would've been over 400 gallons. Even if you use the best per tank MPG of 41, it would still be 350 gallons, quite different from 200.

So, how would you come about deciding how much fuel used would be the indicator for when to change the oil? (in a basic DD).

 

Well, I had a nice long write-up on this somewhere on here. Found it and went to update it with collected data and poof its gone.

*sigh*

Anyways, for a stock Fit in the lower 48, using a high quality filter, E10 or E0 fuel, an Oil with magnesium/calcium in it and a virgin TBN of at least 5 it would be wise to change the oil every 120-160 gallons of fuel.

This is assuming you let the engine get up to temperature and have a commute of more than ~5 miles, shorter than that and it would be wiser to use a shorter interval.

I would start to decrease the interval every 25k miles or if you will be driving harder than normal.

Again, I had a nice detailed layout but it was deleted somehow in the posting process.

Specific cases, operation habits and environments would change this as well. Most owners should understand that regardless of how you think you drive your car, you are likely subjecting it to "Severe" service. Especially with short trips. It may be counter-intuitive, but the majority of FF.net members aren't engineers, chemists or physicists that deal with this subject routinely.

Use severe service guidelines if you expect to own the car past 100k.

For special cases like supercharged or turbo fits, the intervals would be considerably shorter because of the added stresses, fuel dilution and blow-by.

 

So considering an average MPG of anywhere from 27 to 40mpg this represents an oil change interval range of 3,240 to 6,400 miles. This is pretty conservative.

The last Honda I owned was going strong at 225K miles after 12 years changing at the Honda recommended interval of 7500 miles. It was very normal service being a commute of 25 miles each way with very few short trips.

Here's a novel idea: