Hi I have covered approx 1500 miles since acquiring my mx5 it has used approx 1 litre oil it has covered about 145000.00 miles no obvious tell signs of burning oil (although smells a little oily at start from cold.
What is the normal oil consumption and what should I check out?
I think most cars consider normal consumption to be around 1 litre per 1000 miles so yours seems to be well within manufacturers tolerances.
Considering the mileage of the car I would be quite happy with that.
Cheers
Tony
So over a normal say annual mileage of 10k it is normal for an engine of that mileage to consume 10ltrs of oil, I don’t think so!
My 1.9 diesel engine has consumed less than 1ltr of oil in 7k miles, and they do seem to use more oil than petrol engines.
Mick
No neither do I.
I’ve never owned a car that used that much oil ( 10 litres in a year ), in fact never used that much over three or four years, which is how long i normally keep a car!
Thanks for responses …so it would seem that its time for another engine then
Oil consumption like that was acceptable for an early eighties BL Montego but is rather excessive fo an MX-5. If there are no obvious signs of it burning it ie blue smoke then check for oil leaks, though i would expect to see some evidence on the ground if using that much.
Likely places for leaks could be crank seals (if it was the rear it would leak into the bell housing), cam seals, cam cover gasket, or CAS sensor (at rear of head).
Check these out and see what you find.
no evedence of leaks
Manufacturers sometimes quote oil consumption figures. In my civic manual it sates that oil consumption of up to 1 ltr per 1K miles is acceptable. If you dont believe me I will scan the page in and show you!
I agree most cars dont use that much but it would not always be considered a problem if they did. My honda civic uses about 1/2 lt in 10K miles but I wouldnt be worried if it used more.
Back to the original question,
If you really suspect the engine get a compression test done. It will show up any worn bores leading to high oil consumption. Very easy to do or cheap at any decent independant garage.
I would say if there is no blue smoke from the MX5 and compression is within tolerances it could be seeping out while driving and not noticable. Have a good poke around under the car for evidence of a minor leak as it may not be dripping on the road or drive way. Also worth doing basic checks such as making sure the oil filter is nice and tight. These engines are very tough and with the milage on yours it should still be a good engine unless its been neglected over the years. Good luck
you guys are starting to get me worried now.
if i put in a cupful between oil changes then i think someting is wrong. ok, mine has only done 130,000k but i dont think the old 5 uses a lot in general (unless thrashed all the time)
Mine uses about 250ml a year. (5000m).
Well I change my Oil every year having done about 4000 miles and never have to put any in between oil changes to keep it at the “Max” mark but my car has only 29k on the clock.
However it is not unreasonable to have to put in up to half a litre per 1000 miles particulary on a car of mileage as the OPs.
The most common cause of oil consumption/loss in a high mileage car is worn valve guides and unless there is a significant leak somewhere, it is where I would look first.
Whip the plugs out, and have a look at them, that’ll tell you how the engine’s performing.
Obviously if they are black and wet with oil then there’s your problem.
Get a compression test done also.
Mick
Don`t panic, have a read of this one… http://www.mx5oc.co.uk/forum/forums/t/24055.aspx or if that one isnt working this one http://www.mx5oc.co.uk/forum/forums/t/24055.aspx 
Dr. Eunos