Trying out 0w-16 oil for more MPG

[arcosine]

After running 0w-20 in the Saturn sc1 for 10 years, 75k miles, I decided to change the oil with 0w-16. Should give 2% mpg over 0w-20 and 7% over 5w-30, spec for sc1. Been getting ~40 mpg. New oil should give 41 mpg.

[rmay635703]

How many gallons of oil do you burn?


I have considered the stuff for the 2000 Insight but the 0w20 Synthetic gas truck oil was so cheap and it quiets the engine down compared to the Mobil AFE

[serialk11r]

Do let us know if you see a big difference.

I would only be okay trying out a drop in viscosity grade if I knew the oil temp. High performance cars that have 50 or 60 spec from the factory are supposed to run okay at 260F on the track where the oil has thinned down to around 11cSt, but you're not supposed to go much below that or the bearings take damage on some cars (cough BMW).

A car with way too much oil capacity or aggressive oil cooling might have trouble getting oil temp over 180F on the street, and 0w-16 would be at a perfectly fine viscosity of around 9 cSt there if the engine was originally supposed to take 20 or 30.

So rapid damage considered and avoided, the question becomes is it worth it. Supertech brand synthetic oil is what, 15 bucks a jug? Mobil 1 AFE 0w-16 is 23, and Mobil 1 is not really known for having good anti-wear properties AFAIK. If you get a 1% improvement in FE, you're looking at 800 bucks of gasoline before breaking even, and that's a LOT of miles, and risking more bearing wear at the same time.

[cowmeat]

How many gallons of oil do you burn?

I thought the same thing!

If I put it in my old Chevy 3500 I'm pretty sure it would just pour out the bottom at the same rate I was pouring it in the top, and would seize the motor as soon as I tried to turn it over even if I could get it to stay in there

[rmay635703]

Originally Posted by cowmeat

I thought the same thing!

If I put it in my old Chevy 3500 I'm pretty sure it would just pour out the bottom at the same rate I was pouring it in the top

Some of my friends owned older Saturns, both burned oil but one quite literally needed oil added everyday using the stock grade oil.

It didn’t smoke but burned about as much as a 2 cycle

Likely could of used old HD30 without much fuss

[arcosine]

I don't burn it, I give to a friend that uses it to heat his garage.

Car doesn't use much oil, haven't kept track, seem to be less that when I first got it. Maybe a quart in 2k miles, it has 175k on it. I'm running it with crankcase vacuum.

Originally Posted by rmay635703

How many gallons of oil do you burn?


I have considered the stuff for the 2000 Insight but the 0w20 Synthetic gas truck oil was so cheap and it quiets the engine down compared to the Mobil AFE

[Fat Charlie]

Instead of thinking mpg gain, look for the percent change in gph at idle.

Get it fully warmed up, then let it settle at idle and see how many gph you're burning. Then change the oil, get the new load fully warmed up, and see how many gph you're burning now.

[Ecky]

Not 0w16 but related: I'm considering running 0w20 in my engine after I run through my stock of 0w30, and could use some opinion.

The K24A2 in my car calls for 5w30 and was never later spec'd down, while most other Honda engines from the period were. For example the K24A4 in the Accord was originally spec'd for 5w20 and later given "0w20 also ok". That engine is extremely similar, but has lower compression (9.7:1 vs 10.5:1), a lower redline (6800rpm vs 7100rpm), and less horsepower (160 vs 200) which is mostly from camshafts and smaller intake and exhaust diameter. Aside from different camshafts, pistons and rods, they're basically the same. Bearings even have the same part number.

Later revisions of the K series all call for 0w20, even ones with the same horsepower and redline. But again, Honda did not back-spec this particular engine, when they did that for most others. This is the highest factory torque and horsepower of any K series.

I live in a cool climate. Without a grille block, I have a hard time getting it up to temperature any month of the year, but especially in winter. I have no way to monitor oil temps but I expect they're not high. I'm planning on adding the coolant/oil heat exchanger from another K series soon, mainly to help the oil to get warm. I have also reduced the rev limiter from 7200rpm down to 7000rpm.

On the other hand, I have an under-driven oil pump (which probably still has pressure limited by the relief spring). I run much more advanced ignition timing (5-7° at WOT), meaning there's more force being applied to rods and bearings. I also do drive spiritedly in short bursts - it's not particularly rare for this engine to bounce off of my rev limiter.

Thoughts? 0w20 probably fine? Even thinner? What would you do?

Edit: Under what operating conditions will lower viscosity oil most likely become a problem? Is it low RPM high cylinder pressure, or high RPM operation?

[roosterk0031]

5w-30 in everything but the 2 cycles, don't care about the spec. A few % mpg isn't worth it.

[rmay635703]

Originally Posted by Ecky

Not 0w16 but related: I'm considering running 0w20 in my engine after I run through my stock of 0w30, and could use some opinion.

The K24A2 in my car calls for 5w30 and was never later spec'd

On the other hand, I have an under-driven oil pump (which probably still has pressure limited by the relief spring). I run much more advanced ignition timing (5-7° at WOT), meaning there's more force being applied to rods and bearings. I also do drive spiritedly in short bursts - it's not particularly rare for this engine to bounce off of my rev limiter.

Thoughts? 0w20 probably fine? Even thinner? What would you do?

In your application I wouldn’t, I would stick with 0w30 (which carries zero risk)

If you put lower spec oil listen to your engine and do a UOA on it.

A single bout of lower spec oil in “normal driving” will sound noisy but likely not cause failure

In my cars where I tested this it made them much noisier.

If you send in a UOA and notice high metals no sense continueing

I would recommend Rotella Gas Truck full synthetic 5w20 if you want to test a 20w, it seems to be on the heavier end of 20w and is more sheer resistant
Even better it’s on clearance many places for $10 a 5q jug