I have two questions about adding oil. Should I keep a can of it in the trunk? Then when I add less than a can should I just toss the partially used can or is there a way of keeping it spill-proof in the trunk?

IS it better to check the oil level with the engine cold or hot?

 

The passthrough cubby thing holds 2 quarts just fine.

 

and it wont spill in there

and check the oil when your engine is warm, but about 10 minutes after you shut it off so the oil settles

 

last first. check the oil after it is warm. once it is warm turn the car off and wait like 5 minutes then check it.

first last. yeah keep a quart in the trunk. also keep a zip lock freezer bag with it. that way when you use less than the full quart you can close it up in the bag to prevent leaks. the other thing to do to prevent leaks is to keep the bottle from banging around in the trunk. the best way i have found to do this is to keep it in the pocket in the pass thru door. it is accessible from the trunk(if you dont have the spare mounted) and also from the passenger compartment by opening the pass thru. the quart fits perfectly there.

edit: guy is a FAST poster!

 

I keep mine in that pass through pocket. I put it and a rag in a plastic grocery bag, then in the pocket. Always have a quart ready that way.
But, when I am at home checking (most of the time), I use a quart from the garage, the one in the trunk is for emergencies, or when on a long trip.

 

yep rag is there too.

 

stupid question time.... why should the oil be warm? Wouldn't it be better when it has all drained back into the oilpan when it is cold to measure it?

 

Asked/answered here:

https://www.rx8club.com/showthread.p...threadid=16510

rx8cited

 

I dunno why it should be warm...I've always checked oil when warm on every car I've ever owned 'cause EVERY car I've ever owned specified clearly in its manual to check it when warm. Plus, my Dad told me to, too. (Sorry, couldn't resist being a smartass.)

Sometimes it's OK to check it when cold to determine if there's enough oil in the engine to risk starting it. This would not be the case for most any RX8 on earth yet, unless there's a puddle of oil larger than the car beneath it due to failed oil cooler hose seals or it's seen major track time at last run. (I'm thinking of my leaky 1976 Alfa Spider in my garage which hasn't been run since October -- I'll check it before starting.)

A techinal explanation: some bits of the engine expand and others contract when it warms up. You can't get an accurate measurement until all the bits are at something close to operatiing temp.

Waiting 10-15 minutes after shutting off the car is also recommened -- at least on a piston engine as a good bit of oil collects on top of the cylinder head(s) and should be given a chance to run down to the sump. Don't know where it collects in a rotary, but I expect it collects somewhere. I'd say you've got an hour window on the checking, really, as the engine and oil is still pretty hot even then (AMHIK).

 

In practice I’ve found that checking the oil in my RX8 when cold is fine, as it gives an almost identical reading to the ‘heat and wait five minutes’ method.

The most likely way to get a false (low) reading is to check the oil immediately after stopping - i.e. failing to wait 5 minutes.

But car makers need to give a simple single instruction for owner procedures and not complicate the issue with multiple choices. As the article linked to above by rx8cited points out, most checking is done at a garage with a warm engine. This can give a different reading on the stick from a cold check depending on how long the warm engine has been standing before the check is done (i.e. how much oil has had time to flow back into the sump).

Mazda’s instruction to wait five minutes before checking the warm engine allows most of the oil time to flow back into the sump, and some general settling to happen. Specifying the time should also ensure reasonably consistent conditions.

Oil will expand in volume during use, partly due to the heat and possibly partly due to a degree of aeration, depending on the driving. But the full available volume will not quickly run back into the sump anyway. In my experience, if the five-minute rule is followed, these factors balance out to give a very similar reading to checking when cold (in our fairly moderate climate, anyway).

Perhaps some owners in more extreme climates might like to try it and see if they can see any difference? Certainly, when I’ve checked it when cold and then later using the warm oil/wait 5min method I couldn’t see any difference either with the naked eye or when actually making a measurement of the oil level on the dipstick.

 

I have a tool box in the trunk that holds two quarts of oil in resealable containers, in the bottom. I also have a screw-on extension for the oil that has a shutoff. That makes it easier to get the oil in the fill area. The top of the tool box has lug nuts, lug adapter, stock lugnut unlock tool, flashlight, etc. My snow wheels use a different lug nut than the stock wheels...

 

I'm going to purchase a bottle to keep in my car... what do the majority of you use?

 

Castrol - see results of this poll . /rx8cited

 

There are other threads on selecting an oil, including the endless dino/synthetic question. I carry the same oil my dealer puts in the car.

 

I go 2000 miles before having to add a quart, why carry one around all the time? When It needs a quart I put it in in my garage (where I have a case of Castrol 5-20).

 

I found that if you have the emergency tire inflation kit, you have a great place to carry a quart of oil. Just loosen the strap around the kit, set the oil there and tighten the strap back down.

 

when i get gas i check the oil. no waiting. cept the time it takes to slide my card tell the computer no receipt, then select the fuel type..after i get it going on its own, i go around and check the oil. (sure is clean..first two times i was like "oh crap there aint no oil" ..very cold out and lighting was not that great.

 

So you check the oil right after you stop?

 

pretty much yeah i am not going to hang out at the pumps all damn day.