Build Thread: Max City MPG from a $250 1991 Geo Metro

[Jim-Bob]

I actually got out and drove it today. I am surprised at the acceleration as it is quite sprightly! I think I could go with a taller final drive ratio and it would be just fine. I also found a wasted cam seal that I ran out of time to finish replacing. It was puking 1/2 a quart of oil every 40 miles or so so I decided to fix it before I drove it again. Sadly though, I also did a compression test and it came up lacking. The lowest cylinder was only 110 psi and the highest 150 with the other being 140. It's on it's last legs and probably has a burnt valve. I'll drive it for a few months until I can afford to finish the other engine and then I have to decide which car to build.

[Jim-Bob]

Another minor tragedy beset my Metro project today: I have a fuel leak from the gas tank. I filled the tank so that I could start getting baseline fuel economy numbers and noted the smell of gas. Looking under the car, I saw the whole back of the tank wet with fuel. I guess I will have to figure out the problem and try again. I also figured out that the previous owner most likely removed the thermostat which is why the engine does not warm up. This is keeping the engine out of closed loop and maximum fuel economy. I will be dealing with both of these issues and two oil leaks next week. Hopefully I will be able to start logging my fuel economy soon as I am anxious to know just how good the numbers really are.

From what I saw tonight ( the first time using it for delivery), the numbers seem to be fairly close to at least my bottom goal of 40 mpg city and possibly a little better. However, it is all just speculation at this point as I have no hard numbers to back up my gut feeling. (I am just judging it by the average numbers from my truck and the average cost per delivery that it usually runs me. Normally, a 10 delivery night runs $8-10 in fuel. I managed to see $15 in fuel get me through 20 deliveries plus 50 miles of other driving with 2 gallons left to spare. This would seem to indicate roughly 40 mpg but again I am not seeing that as fact until I can get repeatable concrete numbers to prove it)

[Jim-Bob]

I figured I would add the only progress shots I have. They are of the interior after removing the carpet and seats, scrubbing them with Simple Green and a thorough flushing with a pressure cleaner. It was THAT dirty. I finally reinstalled them a few days later after they had dried out. I still need to find a new driver's seat ( or a passenger's- they use the same cushions and upholstery) and a better piece of carpet but at least it no longer smells of dog and mold. Luckily though it is a non smoker car so at least that foul stench didn't have to be dealt with.

[Jim-Bob]

I fixed the gas tank as of today. It took a full week to get the part in ( pump gasket) and it was the very last one NAPA had in the country. I also took the time to replace all of the rear fuel hoses and the filter while I was in there. When I finished, I took it to the gas station and filled it back up. Last time, the gauge quickly fell to 3/4 of a tank, but this time it held steady at full. Even still, despite the leak and lack of closed loop operation, I still managed to hit 37 mpg. However, I have decided not to include this tank in my data set as I feel that it is not a true baseline representation of what the car is capable of. The current tank will instead be my first tank with nothing substantial changed except for the 195 degree thermostat. Well... and the lack of a massive fuel leak.

[Jim-Bob]

Success! My first tank without a fuel leak is 41.93 mpg-all city. I consider this an excellent baseline to build from and hope to see a 50 mpg city tank within 6 months. After all, the engine I have now has a weak cylinder and the tires and gearing are far from ideal not to mention I have no instrumentation yet. My only modifications were to increase the tire pressure to 42 psi ( from a max of 35) and the use of a 195 degree thermostat ( which may be the stock spec). It even has the stock hubcaps.

[Jim-Bob]

Ran a new compression test today and the engine came back with a clean bill of health this time. It got a 165, 165, 162 today versus 110, 140, 150 for the same cylinders last time.

[darcane]

Originally Posted by Jim-Bob

I do not have the torque converter clutch hooked up in that car as I eliminated the computer and went with a Quadrajet from a 1979 Chevy van. The Quadrajet is another secret with that car. The small primaries of a Q-Jet give very good throttle response due to higher velocity through the small venturi and allow the car to run at basically a high idle in most circumstances.

FYI, you can run a TCC lockup even without the computer, assuming you're still running the 200-4R or a 700R4. You can wire up a manual switch to turn it on, or buy one of the many kits out there to includ a vaccuum circuit.

I've got a 700R4 in my '68 Chevy pickup and I just wired up a toggle switch leave the switch on all the time. Since lockup is only in 4th, when it downshifts it turns it off anyways so it's not like it bogs down or anything.

Mike

[Tango Charlie]

Excellent news on the compression test, Jim-Bob. Sounds like she just needed to have the cobwebs knocked out of her.

P&G and DWB will get you a long ways to your goal.

I sorta, kinda miss my pizza delivering days. It was fun. One time, I remember making a delivery to a subdivision that I wasn't totally familiar with. I was so focused on finding the address that when I got back into the car after making the delivery, I had absolutely no clue where I was. It was like someone wiped my memory banks. It was kinda creepy, actually!

[Jim-Bob]

I'll be happy to be done with pizza delivery. I have done it for 16 years and am so tired of it that I am selling my house and moving back home so that I can go to college full time. The problems I have with it are: the pay, the hours, the lack of benefits, and the people I work with. None of them are very intellectual and I guess that is to be expected in such an environment. However, it leaves me with no one to relate to and socialize with. I'll just be happy to make a decent salary and work Monday-Friday, 40 hours a week.

Oh, second real tank today: I broke the 43 mpg barrier! Granted this included 150 miles of highway driving, but still a good number.

[Jim-Bob]

Minor update on the car: My scavenging abilities have netted me a big part for the interior- a center console out of an early Dodge/Plymouth Neon. I still need to locate another power port to wire into the console for charging my cell phone, but this puts me one step closer to my eventual MPGuino install. I wanted to fix a lot of things with the dash ( the giant water leak from the cowl through the A/C system being one of them) and so I am gathering the parts to do all of it at once. I still need a tach cluster as I plan to use a smaller screen for the MPGuino and install it in the tach face like another member on here did.

I also scavenged some fairly decent speakers ( 5.25 Infinity coaxials for the front and Rockford Fosgate 6x9's for the back- $22 for all 4) and am busy building some mounting solutions for them. Likewise, I am also adding a few pounds of sound deadening as GM/Suzuki didn't see fit to use any from the factory. Early Metros are very noisy inside because of this and I have tinnitus so I need to keep the noise level down for my own sake.

All in all this is a fun little project for me. I get to solve problems and invent new bits and pieces to make this cheap car better. I've long since decided that that is what is most important to me in the car hobby. It's not about winning a race necessarily but rather about intelligent problem solving.