40MPG with 97 metro - good or bad ?

[chris82369]

Looking for tips, suggestions, feedback on my experience with my recently purchased 97 metro...

I just finished my 3rd tank of gas on my 1997 Metro: 2DR 1L, stock, 114K miles, no modifications, tires at maximum pressure. The previous owner says the engine was "rebuilt" before I bought it, although I think he did not do a valve job, just new rings, bearings, timing chain, etc. Generally driving performance seems to be ok.

My MPGs have improved with each tank, mostly do to scangauge and driving technique. I averaged 40MPG on my last tank. My driving techniques include killing the engine at stops, and a little EOC when coming up on stops.

Many of you here seem to exceed 40MPG, some by a lot. So I wonder if my car is not running optimally, or maybe it is the nature of my commute that is effecting my MPGs. My commute consists is about 11 miles each way, probably 80% freeway miles, but these are some congested 65 mph speed limit freeways (I generally try to no more than 60mph), generally flat but a few over/underpasses. Generally my average trip MPG is still creeping up by time I get to the end of my trip -- so I wonder if some of you guys getting better MPG are driving on longer, slower and/or steadier trips ?

I did a compression test (throttle open, clutch in per shop manual), and here are the numbers:
cylinder, psi
1, 167
2, 160
3, 140

The shop manual says expected is 199, and min is 156, and max diff between cylinders should be 14. So it seems like my cylinder 3 is weak. How much would this effect my MPGs? Is this most likely the valves ?

The spark plugs look good, and the cables test good 7-10k ohm.

I checked the timing and it already seems to be advanced a degree or two from the shop manual suggestion, so I left it alone.

Chris

[Johnny Mullet]

It will run with low compression numbers, but will not run or perform as expected. My wife's recently rebuilt 97 Metro averages 47 MPG. No freeway driving.

I would save up some money for parts and consider rebuilding the head...........
1.0L Head Repair Guide
Detailed 1.0L head rebuild guide

Buy stainless steel valves and get the new head bolts from 3Tech Performance and a head gasket kit from Felpro.

Good luck!

[chris82369]

Thanks Johnny. I guess I knew the low compression was probably my main issue, and the valves needed some work, but I was hoping for some other miracle solution.

[Bicycle Bob]

You are probably loosing by turning off the engine for less than a minute, unless you bump-start it. Using the starter gives a big shot of gas, on many cars. On a metro, the valves are the first to go, followed by the rings. The bearings seldom need renewal.

[5speed5]

Just want to make sure you're holding the throttle body open when doing the
compression test. Some people forget to do that. 40 mpg sounds low to me.
50+ mpg should be the norm for a Metro driven as you describe (assuming it's a
5-spd manual). However, I notice you're in CA. You could be the victim of
oxygenated gasoline.