How much is "normal" engine oil consumption?

[SunnySideUp]

I know this is a loaded topic and that there are a lot of ifs-ands-or-buts associated with this question. Assuming a leak-free and well cared for engine with approximately 50K on it, what would be normal amount of oil consumption in 3000 miles? The research I've done and questions I've asked several mechanics have done very little to provide a common answer. I have heard everything from "negligible" to a full quart every 1000 miles . What should it be with normal driving conditions (i.e., not a track / auto-cross car)?

[So Cal Mark]

anywhere from none to 3 qts in 3000 miles could be normal

[narfire]

I might do that over the 8-9 months I drive it and perhaps 1 liter goes missing. 20-50 wt.

[toplessexpat]

Absolutely zero in the last 3k for me.

[redcars]

My 82 used a qt in 500 miles with bad valve seals and a qt in 2000 miles with new valves seals on a engine with 100,000 miles on it and no leaks. On a trip last year I had a cam box gasket fail on the intake side and used a qt in 100 miles for 700 miles. Boy was it a pain to get the under side of the car cleaned up oil was on everything. As long as you keep oil in it I really does't mater how much it uses. Oil is cheaper and easier to add that parts.

[DanD]

I think in the old days, a lot of the engines I would tear down would have a ridge at the top of the bore, but they still had good compression. Most of them would have bad exhaust guides by 100,000 miles, and would puff smoke on acceleration and deceleration. The silicon bronze replacement guides seemed to fare much better, but it could have also been due to the fact that people would start these cars up and run them right up to red line without any warm up. In any case, it was always the exhaust guides that were reamed out, but some of the stoutest fiats I have ever driven puffed smoke.

Is your car smoking on downshifts ? Smoking like an insect fogger ?

If you drive a brand new Porsche, Audi, or Subaru WRX and it consumes less than 1 quart every thousand miles, they will tell you that there is nothing wrong with the engine. Oils like Mobile One are actually designed to burn clean and run through your cat without damaging it.

[WYSpider]

Mine doesn't consume oil it just leaks it.

[bobplyler]

I used to have a Corvair. I never changed the oil, I just put in 1-2 quarts a week.

[majicwrench]

All engines use oil, they are designed to use oil as they lubricate the cylinder walls. All engines produce various things-- moisture, by-products of combustion, un-burned fuel-- that end up in the crankcase to replace oil that has been burned. So when someone says "my car doesn't use oil" that is not true, it is simply using oil and replacing it with junk.

Normal??? that could be anything. I put a quart into my 72 (which puffs a little on some starts, leaks a little) every 400 miles or so.

Are you having a problem??

[TX82FIAT]

Three spiders and three different oil consumption patterns. 79 burned oil to the tune of a quart every 500 miles. Current 82 does not burn that much oil, about a quart every 1000/1500 miles. The 83 only had to have the oil touched annually when i changed the oil. The dipstick never read low. All three cars ran well with not significant signs of smoke.

I do notice a very slight smell of fuel in the oil when i change the oil on the 82. Compression is outstanding and even on all cylinders. again, no smoke or gas smell when driving.

Is there a chemical test to check oil/fuel mixture?

[DanD]

Three spiders and three different oil consumption patterns. 79 burned oil to the tune of a quart every 500 miles. Current 82 does not burn that much oil, about a quart every 1000/1500 miles. The 83 only had to have the oil touched annually when i changed the oil. The dipstick never read low. All three cars ran well with not significant signs of smoke.

I do notice a very slight smell of fuel in the oil when i change the oil on the 82. Compression is outstanding and even on all cylinders. again, no smoke or gas smell when driving.

Is there a chemical test to check oil/fuel mixture?

IIRC, there is no PCV valve in the breather tube on fiats, but there is a spark arrestor in the hose that is like a wire mesh ball. If that gets gummed up, it could prevent gas and gasses from being properly vented out of your sump. The device is just jammed into the hose.

I'm sure someone could confirm this, it has been 30 years since I last looked at one...

[fiat218]

I thought a 1/2 a quart was normal in any car/ truck

[TX82FIAT]

I had to replace the little elbo on the tube last year and checked it all out then. The spark arest is clean. I see some kits to test for fule in oil but it looks like they cost about 30 dollars.

Engines will all have thier nuances for oil consumption. As my old Italian uncle would say. if it aint broke don't fix it. If the car is running fine then moderate oil consumption shold not be an alarm.

[baltobernie]

Is there a chemical test to check oil/fuel mixture?

Yes. Here's a sample report from one company: http://www.blackstone-labs.com/gas-engi ... port-1.php

[SunnySideUp]

Thanks everyone!

Are you having a problem??

Based on everyone's input so far... apparently not. My Spider runs well. Just seems these engines like to drink oil. I was just wondering if my experience with the engine consuming of a quart about every 1000 miles was a sign of something going wrong. The tail pipe residue is black but not oily. I'd prefer it to be more coffee colored like my other cars. I have not noticed a puff of blue exhaust at start-up or deceleration. Other Spiders I have had didn't consume oil like my current one. The '80 I had with 75K used close to a quart in 3000 miles. I will definitely be checking the valve seals when I do the next adjustment. For now, I'll just keep an extra quart of Rotella on hand.