Without a scangauge, or some other feedback device, I wouldn't drive in such a high gear, yes, you can drive very carfully in a high gear, but even the slightest nudge of the gas pedal could make it dump extra gasoline in, making it run less efficently, and making your mileage drop.
That's actually a really good theory. Next tank I'll try driving in 4th instead of 5th at 30mph and see if it makes a difference. My car is REALLY poorly equipped... it doesn't even have a RPM guage!
Does anyone know where I could get a Scanguage-like device for less money? I like buying things used instead of new. I thought about ripping one out of an old 80s Cadillac in a junk yard.
On the 1 liter 3 cylinder the valves don't hit the pistons according to my friend service manual but that depends upon the year. A worn belt can cause some timing fluctionations in the valves and the ignition timing. With that many miles on the engine I would probably check the belt to see if there is anything left of it ASAP.
Thats an odd , question....I will just see if I get that rite.
Does valve lash (the summed clearance of valve train parts) increase when a timing belt fails.?
When the cam timing belt breaks it is typical that most engines will get bent valves.
Then valve lash is the least of your trouble.
That sounds like valve 'crash,' not 'lash.'
BTW, even if you don't know if the plugs have been changed in 146,000 miles, take them out and look at them anyway. You can tell a lot about your combustion from what the plugs look like (too rich, too lean, oily, etc.). Of course when the electrodes are all eroded away, you'll wonder how it worked at all (don't ask how I know this). Then just put new ones in.
As for a new air filter, it will help keep the engine breathing freely and atomizing gas efficiently. On my Passat, there was a screen (I think it was a snow filter) in the intake box. All air had to come through it but it was clogged with years of fine road dust. After I scrubbed it with carb cleaner, my FE improved noticably.
Reality is merely an illusion, albeit a very persistent one. - Albert Einstein
Peakster, if you're getting EPA mileage @ 55/60 mph in steady speed driving, you're doing about as well as you can expect from a regular Metro. There's nothing wrong with your car.
I've owned 2 Fireflies, and they are without question the most optimistically EPA / NRCAN rated cars I've had (had lots). Check my speed vs. mpg graph here for the story in a nutshell: http://www.metrompg.com/posts/speed-vs-mpg.htm
The only reason I'm getting ridiculous numbers with my current car is because (1) I don't drive in real-world (ie average) conditions, and (2) I use hard-core hypermiler techniques (3) on top of numerous tested mods.
The engineers either tried awfully hard to spec the cars to excel in the government test cycles, or they just got lucky.
The Metros will not excel at highway efficiency without extensive aero mods, through which you may be able to gain a 15-18% FE improvement at speeds around 55 mph.
They have excellent potential in low/medium speed pulse and glide/ CODFISHing due to the low weight and low engine power.
Seriously though: get a scangauge. Watch eBay. The used SG1's are going for around $75 US these days. It'll pay for itself, and you can bring it with you to your next vehicle.