sure,
the more compression the more power, but you will need higher octane fuel $$$ to do that.
in fact this is the cheapest way (parts only) way to get power. (milling head or thinner head gasket)
sure MPG tells you 2 things
the EFI has not gone nuts. (limphome or ?)
and then engine is healthy and efficient.
and brakes are not dragging
and tires are not flat.
low compression. good mpg
you must know that many colleges have taken cars and killed cylinders , to get more MPG, right, but can go to fast.
think like this,
what is the weight of the car.? that is 1st
then how fast you want to go.
the best MPG at that weight and that speed is an engine that has just exactly the perfect HP to do just that job.
this is why many new cars drop cylinders. (called VDE, variable displacement engines.)
there are many college made cars that have only 1 cyclinder and have school contests , all great fun .
and this, long ago VW made a car that got huge MPG, but what did they do, the got rid of all that weight.
real 84mpg
with a carb.
id bet i could get 100mpg, with EFI, now.
http://www.youtube.com/watch?v=9XUKOUbp_PA
how low can you go?
well that is a matter for EFI.
the 16v has no lower limit, but may get very unset below 150 PSI, (below here some where) but why worry that
we check compression if say one cylinder is low, say 140, and oil added dont bring it up, the valves are burnt.
burned valves is a death call, DOOM SOON...... pointless to worry why the efi is upset and if the intake valve burns , that sends a pressure wave back in to the induction
making them upset the the MAF to go nuts.
how low is not the issues. ever.
sure the EFI runs great when the rings are old and pressure drops a bit.
lets now play game 2, the 16v head, is say, brand new,.
and the rings are bad.
rings can fail 2 ways. (not counting oil control ring and its drains) "rings bad, or not seating to cylinder, the walls are bad,usually both"
(my first instructor in 1965 , had this really cool engine. a 1950 chevy I6, with
like 500,000 miles on it. (the naked car for training only)
he asked us, to get it started. grinning. (perfect carb. / spark,/ starter) perfect clean fresh fuel.
most guys could not. (expected)
the engine had rings, as thin as razor blades. compression was pathetic, say 80psi? (like a lawn mower)
we started it with ether. and with fast right foot could keep it running, the body was missing but had a seat on the frame and could drive it in our school field. (was a SLUG !)
why did he have us do that.
to learn how a low compression engine runs. it was gutless.
lessons to learn
1: yes, compression matters, if wrong, there may be serious doom going on, unless rings are paper thin, but they would snap if we over-rev'd it.
2: no matter how much spark and fuel you dumped to it, it was hopeless. (a turbo would cure, it or blow the rings to dust 'BOOM")
Compression is a spec, if not at spec, then something is wrong, and will get worse fast, say not setting valve lash and burning the valves up.
some times rings are bad due, to cooling system failure, and overheating them and the cylinders look like hell scored to death,. a hopeless engine. again. the can warp cylinders and round rings just hate square cylinders. 1/2 joking..
i bet your's is ok. it's only a 20 buck tool and 30min work. (wot , hot or warm, and cut fuel)
