I use conventional oil in my 09 Fit Sport. I find I need to add a bit of oil between oil changes, and so ordered some 5W20 from Bernardi. They shipped me Honda Synthetic Blend oil. Can I safely use that to top up my conventional oil? Thanks in advance.

 

You have much bigger worries if you are burning/leaking oil in a car that is a year old.

To answer your question: yes, you CAN mix them. But I wouldn't, and I doubt Honda would be cool with that either.. Engines are expensive, oil isn't.

 

Synthetic blend is already a mixture of regular and synthetic oil. All the oil companies say it's fine to mix them.

 

it's fine.

Any oil that has the same starburst API specification and service class is compatible. Mixing will just blend any slight differences in characteristics and you should treat it as the "lesser" oil.

This is the purpose of having a specification-to ensure compatibility.

Even during an regular oil change, about 1quart of your old oil remains in the system, so mixing happens under normal circumstances.

 

Thanks for the replies. Is anyone else seeing significant oil consumption between oil changes? I seem to be losing about a quart per 10,000 miles, which is typically how far I drive before the MM gets down to 15%.

 

I have an '07 with 90K miles. Change at 15%, usually abour 6.5K. I'm never down any noticable amount.

 

1qt per 10k is not significant. Perfect oppourtunity to just change oil instead of topping off. That being said, different oil brands might give you different results

 

A whole quart is a lot of oil in a car that might have 3.5-4 qts in the whole system, how much does that leave in the pan for the pickup? Something is wrong there...

I lose nothing if not a negligible amount between changes in the nearly 3 years I have had the GD or any other car in good health that I've had for that matter.

 

I seriously doubt that my car has consumed 1 quart of oil in since I have owned it.... Maybe 3 ounces down at a couple of changes.... Maybe more now at 10PSI boost.

 

You have an excuse atleast.. positive crank case pressure

 

I have noticed that there are what looks like little blotches of black stuff from the exhaust on the rear bumper and hatch but I think it is from the rich A/F ratio and moisture in the exhaust during warm up.... It didn't happen before the weather cooled off.... Even though it is going to be getting colder I think it wouldn't be a bad idea to use at least 10w30 Mobile 1 instead of 5w30. I'm south of Dallas and I can only remember it getting cold enough to freeze up on the roads maybe 3 times in the last 16 years.... They had the worse snow since 77 in Dallas last year and we had snow on the ground for a couple of days but the roads were fine..... I have the hot water hose to the throttle body bypassed, do you think it would make sense to hook it back up? It has been the way it is for a couple of years but it wasn't as much boost and a different tune.

 

take your car to a dealer. and make them do a oil consumption test. something is not right.

 

That does sound pretty rich what does your UEGO Gauge read under idle and acceleration? Some of that funky stuff could be blowby oil, or blown out the PVC and into the intake mixed with EGR gunk.

If you can find it try Shell Rotella T6.

I run a 5w40 in the Laser for the summer to help deal with the extra heat from having to pass through the turbo CHRA as well as the increased cylinder pressure, and a 5w because it gets cold here, and well thats just what my car seems to like in order to give proper oil pressure rise (10psi/1000krpm) for both the engine (~10psi @950 idle/~95psi @9250rpm and the journal bearing turbo which has its own picky oil requirements and is being run off the head with an pressure sending unit inline. Borg Warner said max 80psi on cold start, 10psi @ idle 30psi min @ cruise and under load with a max of 75psi under load.

You might do well with a 0w30, 0w40 or 5w40 for startup in your nice warm climate and then the 40weight part becomes handy under boost. The GEs come with a recommendation of 0w20 for start up and fuel economy, but you would be under whats considered severe duty service requirements because you are putting out easily double what the car produces stock.

Also if/when you finally wear out and upgrade your clutch disk think about 2/3 Redline MT90 (75w90) 1/3 Redline Lightweight Shockproof (75w140) for the gearbox.

When you finally change your motor mounts you should definitely do it then, if you haven't already.

I have 2 bottles of MT90 (75w90) and 1.5 bottles of Heavy Shockproof (75w250) in the race car.

This is in a 129k mile stock FWD transmission I got free with the shell and am using as I convert to AWD. The gears rated for a max 275lb-ft at the crank from the factory, and it hasn't been below 300WTQ since I have had it!

I have not been particularly nice to it, stock redline was 7000, big cams and springs let me breath on up to 9250, which the synchros hate, until I upgraded to a six puck cerametallic disk the clutch used to drag to, which didn't help either...

Even the heavy shock proof has low fluid friction like a regular 75w90, but provides the protection of 250 weight heavy gear oil for when you bang home shifts under WOT.

 

agreed...like DSM said losing a quart in a car that has about a 4 qt max is something to be very concerned about.

 

Thanks again for the replies. One further question. I'm assuming that a drop from the top mark on the dipstick to the bottom mark represents the loss of a quart. Is that correct?

 

I would require a Fit oil pan to determine exactly, but think about this, 1 fluid ounce of oil is almost 2 cubic inches.

Lets ASSume that the oil pan at the top of the full line on the dipstick is 8" wide and 10" long. Now lets say there is 3/4" from the full line to the fill line.

That gives us 60 cubic inches. Multiplying .55 gives us the volume in fluid ounces.

60in3 times .55 gives us 33fluid ounces.

There are 32ounces in 1 quart. So you are in fact losing a little more than 1/4 of all the oil in the engine over the course of only 6000miles or so.

That is bad. Really bad.

 

I'd try just changing oil brands first. Although my Fit doesn't lose any oil over a normal change, a quart loss over 10k+ miles is NOT a great deal of loss for most engines. I've seen plenty of cars w/ 4.1 and 4.4 qt capacity that state right in the manual that up to a qt loss over a 5k mile OCI is possible. Different engine, but in my CR-V I'm always at least a 1/2 quart down by 5k. But I agree that in this car, it doesn't seem to be that routine. If changing brands doesn't work, you might try something like a run of auto-rx. B/c even if it is "normal," it can lead to other problems like fouled o2 sensor and/or cat converter.

 

It is not a "great deal" until the oil pump starts to cavitate and starve and then your crank wipes your bearings or you window the block with a rod.. besides the car in question is a year or so old.

OP, go to the dealer and find out what is going on if you have not already.

 

Lol, ok sure. The sump capacity is practically 4 quarts in a 1.5l engine. I don't know where this oil is circulating that 1 qt loss is going to leave the sump so bone dry that there's no oil going thru the pickup....but whatever. Emergency!

 

Most engines fill the head under even mild acceleration, and individual engines of the same type return that oil to the pan through the galleys at different rates because of the various casting flashes, gunk and other imperfections that build up along the way.

Seizing or spinning your rod and main bearings is not fun. It is also avoidable and the powertrain is still under warranty. Minor inconvenience now or major expense later on?

You decide.