Prime is coming!

the pip has two trip meters, both with ev and hv miles, so hopefully, prime has even more. i would like three, trip, tank, lifetime.

 

My two views weren't opposing at all. Look again.

And, as I said, he's an engineer. And he works on Indy and Indy-lite cars, not Nascar.

 

My understanding is that water in the oil is the underlying reason for engine sludge and is more likely to occur in a car that

• uses cheap oil
• runs mostly short trips that do not let the ICE reach full operating temperature

So it is not miles per year per se, but how those miles are spread out. I think it prudent to use the best synthetic oil available and plan a good 30+ minute ICE drive once a month.

 

Sludge is from scorched oil or particulates from burnt fuel. There is no avoiding it, but the amount produced in a normally operating engine is kept in suspension by detergents in the oil's additive package. A reason why water, even tiny amounts, is bad in the oil is that it mixes with those particles and forms an acid. Which isn't good for the metal and other parts it comes in contact with. So the additive package contains a base that neutralize those acids.

How much water gets into the oil is a factor of operation and ambient temperatures. More gets into it during the winter, as the water vapor from combustion is more likely to condense inside the cylinder and work its way into the oil.

In addition to the base, other additives get used up with engine operation. In theory, changing the filter to remove the sludge particles, and replenishing those those additives is all you really have to do. Without access to a lab, it is just much cheaper and easier to simply change the oil.

It would be nice if Toyota had an oil life monitor like GM. Either way, the oil change interval on all gas cars should increase with the access to ultra low sulfur fuel next year. Sulfur plays a part in those particles forming.

 

what does the oil life monitor monitor?

 

Looks like it monitors....nothing.

http://assets.cobaltnitra.com/teams/repository/export/975/c7820afba1004895010145efa6b30/975c7820afba1004895010145efa6b30.pdf

"There is no actual oil condition sensor. Rather, the computer continuously monitors engine-operating conditions to determine when to change oil."

 

still interesting though, i would like to know what conditions, and how it can be effective. perhaps gm has done long term oil studies based on engine operating conditions?

 

That's what it says in the document. However, that doesn't really account for different types of oil.

 

do they spec more than one? different vehicles must use different software. i wonder if that is up to date, hard to believe volt is not spec synthetic.

 

The document says it's calibrated for standard mineral oils and that synthetics aren't required.

 

yeah, that seems outdated.

 

They should at least put an hour meter on the ICE. Even my rider mower has one. Then you change the oil based on hours of operation.

 

Our Honda also tells us when to change engine oil. I just presumed it is based on mileage, rpm and maybe engine temperature.

I take it with a grain of salt.

 

i think the prius software takes care of that if you don't shut it down prematurely.
oil change is 10k in the states, so once a year isn't necessary for warranty unless you're driving that much.
agree on the engine, i hate the 124 mile cycle when i have a good ev week going.

 

Correct.

Sounds like a similar system to GM's. Air temperature may also be a factor.

Among the oil additives that are consumed with operation are anti-sieze compounds that provide protect at start up and any periods when metal to metal contact might happen. GM measured the consumption rate of the most common one under varying engine running conditions to develop algorithm tables used by the OLM(oil life monitor).

I assume the OLM works with the oil having the absolute minimum amount of the additive. So better oils might still have plenty of use left.

GM now has their own oil specification; Dexos1. Its synthetic blend, but beyond the oil company paying GM a fee to be approved, I don't think the actual specs are any better than the higher universal standards.

The Sonic requires Dexos1 oil. The HHR did not; just a basic oil. The OLM on both called for an oil change around 7500 miles. The Sonic is a turbo, and perhaps it does consume that anti-wear additive faster. Perhaps GM is just still using the original OLM program. Even so, monitoring the engine operation conditions is better for determining the need for an oil change than simply using a odometer clock. Specially in hybrids; some Volt owners have reported going over 20k miles before the OLM decided it was changing time.

This was once an option for GMC trucks.

Recommend any oil analysis labs?
$15 isn't bad, and I'll use it since the Sonic needs pricier stuff, but last time I checked it was $20 if you wanted the TBN test done. Doing oil changes myself, I could get 5 quarts and a filter for the other car for that much.

Make sure the manufacturer oil change interval doesn't also include a time frame.

 

anyone know what volt owners who rarely drive on gas are getting for recommended oci's?

 

thanks, i thought someone said it was condition based. 2 years is pretty good though.