DAYTA

I use Mobil 1 synth, and my last oil change was @ 10k miles (3rd one). I'm now just under 13k, and my MID is telling me to change my oil already (it's already dropped down to "10% Oil Life".

I would assume that the MID simply counts total RPMs to calculate "oil life", but it doesn't take into account the type of oil being used (dino vs. synth). I feel more comfortable following the MID (which actually falls in line with my archaic 3k miles/change rule), but I'm thinking that if I really wanted to I could get another 1k miles or so out of my current oil before changing it since I'm using synthetic...

DLTSX6MT

We're led to believe that the oil life calculator evaluates more things than just the number of times the engine has turned. But I doubt that oil type or properties are among them.

rb1

I don't think the MID knows anything about the actual oil -- it just looks at various engine operating parameters, RPM, etc.

Someone here said cold starts are a big factor in oil life, which I believe because I drove my new TSX strictly for commuting and hit 10% at about 4300 miles. Supposedly, a long highway trip isn't much worse than a trip to/from work.

Synthetic oil is more resistant to break-down than the MID is calculated for, so I'd feel free to run it to 0% -- I just don't know if there would be warranty issues if the oil life were exceeded.

Also, a big factor in actual oil life is acids that accumulate in the oil. Cold starts are the worse offender in this, as for a brief period after starting you get acidic condensate from the exhaust gas on the cold cylinder walls, which then washes into the oil.

jcbridges

Why are you using synth in a car that Honda does not recommend using synth in?

rb1

Honda has the most lax oil specification I've read in years.

Are you saying that they recommend that you don't use synthetic oil, or that it exceeds what is required.

If it's the former, then I'd want to see a link to something that says "Honda recommends against use of synthetic oil..." etc.

ChrismanTSX

I inquired about switching to synth, and the service manager got back to me about the oil life monitor. It doesn't take into account the type of oil at all...

Depending on your use of the car, it may be worthwhile switching to synth: I'm going to switch at my next oil change, as I live in Montreal (where it gets real cold) and I do a lot of short trips... cold starts being the worst thing for an engine, synth will protect it better.

aaronng

You can use synthetic as long as it exceeds the protection of that of the Honda oil. That is what Honda Australia told us.

ATsxMan8305

Correct in every sense

DLTSX6MT

I rev the hell outta mine, redlining all the time, and don't do a lot of highway miles, and so my MID has been telling me to change my oil after only about 3k miles.

CGTSX07

Honda does not recommend against using synthetic oil. The manual even states that synthetic oil can be used if we choose to use it.

SoCaliTrojan

The MID cannot take into account the type of oil that is being used. If it could, then someone here will be able to show you the device that's installed in the car that can take oil samples and analyze it.

The MID is simply a "device" that is told to assume certain characteristics (grade of oil, etc), monitor other characteristics (number of cold starts performed), and output it's guess as to how much life is left in your oil. It's like a calculator...numbered are pumped into it, and it uses the built-in formulas to display the answer to you.

junktionfet

I switched to synthetic a while back and have not noticed any difference in the "oil life" as calculated by the MID. I still change the oil when the MID says so because by that time the oil looks quite dirty, and regardless of how nonsensical this may sound, I would rather have clean looking oil coursing though the engine. Also, I hear less bearing rattle when I start the engine cold if the oil is clean, synthetic or not. I hate that sound.

clee109

the MID really only accounts for the type of driving you do, according to how high you rev it etc... as mentioned in here. It has no way of accounting for the type of oil being used. Also, if you are using a full synthetic you can squeeze out a few more miles than the MID suggests assuming you are driving like an "average" driver. If you do alot of "spirited" driving than I would stick with what the MID says.

Honda has never posted anything stating that synthetic is not reccomended for our cars, in fact the RDX is only supposed to run on Mobile 1 Full Synthetic. However; if you have in excess of 40,000 miles on your engine and you have been using standard oil during this duration then it is not reccomended to switch because you could spring up some leaks. This is because standard oil can create pours in the oil system and standard oil plugs these pours at the same time. If you run full synthetic through it will clean out these deposits and the result could be leaks.

For the post just above me, after you run your oil through for just 200 miles or more and look at your dipstick you'll probably notice that the oil is alot darker than it came out of the barrel. This is just typical, oil gets "dirty" fast but doesn't mean it's bad. However; following the MID suggestion is the best way to go to be safe.

Also EVERYTHING on the MID is a suggestion. None of it is pin point accurate, this includes your range, mpg, instant mpg, avg speed, etc... The only function that is 100% accurate is the trip time, that's it. So when the MID tells you something other than throwing a warning light (tranny, cel, brake, abs, you get it right?) then take it with a grain of salt. Example, the MID will tell you that service a, b, or c is due because it is PROGRAMMED to at a certain mileage. This does not mean your car needs this service, it is once again, a Honda suggestions. IMO the MID is just one big idiot light.

CGTSX07

just wondering how many more miles can I squeeze out? I am at around 30% oil life on the mid, how low can I go with synthetic. I switched over to synthetic at around 4500 miles when I was due for my first oil change.

rb1

I think it's perfectly reasonable to run your oil life to near 0%, even with dino oil. It will begin saying "Service due soon" at 15% and "Service due now" at 5%.