Lowering Metro by 1.5" good or bad?
 

I just snagged a 1999 Chevy Metro 1.0 three cyl with 130K miles. The question is would purchasing a lowering set of springs help with improving efficiency? The kit says it will lower the car by 1.5".

Second question is would going with Ford Escort 15"X5" aluminum wheels and LRR 145/65 15 tires help vs. the stock steel wheels and 155/80 13" tires.

I like the garden edging air dam idea. That may be my first mod. I am very excited now that I have dropped the big 3.8L Chrysler Town and Country that I was driving 50 miles per day. I expect that I will triple my mileage with no effort a tall. The van was getting an average of 18.5 mpg this Winter. 21.9 during the Summer. You Metro guys are smashing that by a long shot.

Thanks for any input!

Neal:)

The biggest problem with lowering a Metro is that you run out of suspension travel pretty quickly. Inadequate travel can make for some very spooky handling when you hit a bump while turning. What happens is that the suspension hits the stop and makes the spring rate infinite. This will cause the wheel to lose contact with the road as the tire will skip off the pavement. The Metro is already a pretty spooky handling little car as-is. I don't know that I would want to introduce any more possible negatives into the equation. It may well work for a small gain in fuel economy, but all of that economy is a moot point if you get into an accident. Plus, do you REALLY want to be any lower than the bumpers of other cars than you are already? You have a collision interface problem stock. Lowering the car will likely take the bumper and frame rails out of the crumple equation in an impact with a modern car, not to mention an SUV.

Why then ( you might be asking) can people get away with lowering Civics and still maintain good handling? it all comes down to the motion ratio of the strut to that of the wheel. As the motion ratio of a pure Mac Phearson strut front suspension is 1:1, it is very limited in how much lowering it can take without special struts that change the amount of travel they have. On a double wishbone Civic though, the motion ratio is not 1:1 The strut moves LESS than the rate of the wheel because it acts on a point that is inboard of the lower ball joint by a few inches. This means that it loses less range than a Metro when you lower it.

Some things to think about! Best gains in your opinion are from which mod? I got lots of practice with the pulse and glide with my old Prizm 5-spd. Now that you are saying that lowering the car is bad, the air dam now looks like a good idea. Belly pan might be cool also but I don't have a place to work on the car or lift it.

Is the cold air intake good or bad? Would warming the intake charge be a solid idea or am I trying too hard?

Well, probably the best mod you could do would be to put in a taller final drive ratio. If memory serves, you have the worst final drive of all Metros with a 4.33:1. The lowest stock ratio is 3.54 and comes in certain 4 cylinder 5 speed cars. For the highway, that will be your best bet. It should also help the exhaust valves run cooler and lengthen their life. Burnt exhaust valves are the #1 killer of the Suzuki G10. Stainless steel valves are available from 3 Tech and should be considered mandatory whenever you have the head rebuilt. 3 Tech also has a fuel economy head package with a ported head, higher compression and a special economy cam grind. It is said to be worth 3-7 MPG depending on who you ask. I actually have them doing a head for me right now and will be building a new engine for one of my Metros once I get it back. I would also consider something like a Scangauge to help you learn to drive it better.

I don't have too many answers just yet though as I am only on my second day of driving a Metro and mine is used primarily for city driving. I only paid $250 for mine so as you can probably imagine it needs a bit of sorting before I will be able to get any real numbers out of it.

As a new Metro owner, I suggest you check out a few marque-specific forums like Geometroforum.com or teamswift.com. There are specific quirks these cars have and you would do well to learn about them. I also think you should buy a set of factory service manuals off of E-bay. They aren't that expensive and will be invaluable as you sort your car out.

if you are doing highway driving a taller tire wheel combination will lower the rpms at cruise. That's the name of the game. dont go overboard. your looking to increase the diameter by 3-7%. Tirerack dot com can give you alot for specs on tires. Also remember that there is a wieght issue. (previuos posts) each puond over factory is 4 times when it is rolling. so there is more wear on the brakes etc. of course your driving easy.
And the higher psi is a less forgiving ride.

I personally would not use lowering springs. too much for too little. why give up a relatively comfortable ride when an air dam and coroplast underbelly gives you the same results for $60.....

Every metro of that age is starting to rust around the suspension, lowering the car will put more stress on the unibody and could total the car because the parts of the suspension mounts that fail are not replaceable.
To get better mileage a gearing change and a cam change to the XFI (62mpg version of the metro) cam (or cam regrind) would be the best use of your money for improved mileage.

Just drive it as is with stock tires.

Sounds like the air dam and some under body smoothing war within my abilities. Trannies and cams are beyond my range. We have no where to do such work and I can run up a bill larger than what I paid for this rig. I like the sound of all of it

The skinny tires on 15" rims was my thought of reducing the drag whilst trolling the highway. My commute will be 55% highway, 30% secondaries, and 15% stop and go.

Thanks for the input. I will be looking over the air dam information and shooting to do something in Feb. I will have a month of learning the new car and its quirks. Right night the shifter seems a bit stiff and slow to move into the gears. I don't know what would cause that. My old Prizm had a light shifter and was a joy to row. Not so with this one.

Neal

Considering it's winter, do what ever you can to keep it warm. If you haven't already, install a block heater or an oil pan pad heater and some sort of grill block. A front belly pan will not only help Aero. but will help keep the engine warmer as well. I ran a front pan on the Sprint I used to own (long before I knew what ecomodding was) just to get the engine to warm up in the winter. Also, consider synthetic oil in the trans. and engine. If the trans is stiff, it might have gear oil in it. That will make it sluggish and will waste fuel in the cold. These are all cheap and easy mods and the best place to start IMO.

Consider changing the transmission oil. The consensus seems to be that Penzoil Synchromesh is the best oil to use in these transmissions. It is thinner than stock, but it seems to make them shift better if the transmission is not too far gone from someone driving it like it was a 5.0 Mustang.

I will also say that since you just acquired the car you really need to give it a thorough going over. Make sure everything is working properly. Do a compression test. Check the engine mounts. Check the suspension and steering joints. Check for oil leaks. Check all of the brake and fuel hoses. Check the shifter bushings. Most importantly though, check the part of the unibody that the front lower control arms bolt to. This is a place where dangerous structural rust can occur in rust belt cars and could cause the wheels to separate from the car if it goes too far. I own 2 Metros and this was one of the first things I checked when I went to buy them. How did I check it? I just poked at them with a screwdriver to make sure it didn't go through. Now, it can be fixed if it is bad but it does take welding and is a PITA. Just remember that most Metros and other small commuter cars that are 10+ years old have seen a hard life with minimal care and maintenance. If you can do this work yourself though you do stand to reap substantial rewards in terms of efficiency and low cost transportation.

I would opt out on lowering springs. If you suspension needs to be replaced clean it up with OEM parts. Don't look at just springs or oil on the struct/shock. Old parts are just old parts. 100K on a shocks, replace them. Springs seem to sag or have alot of dip under braking, replace them. Go after your suspension bushings and steering components. Depending on driving conditions, a better handling car will allow you to maintain higher speeds and eliminate the brake/gas through turns, corners, ramps, etc.

From someone who has been working with a non-eco minded vehicle let be share of of my best/worst experiences, Maybe it will help you with some guiding light!

Best:
-Scan Gauge/Ultra Gauge (I recommend UG because I have one and it is ~$50-$70 cheaper :D )
-Front bumper air blocks and air barriers.
-Wheel covers/moon discs
-Tire Combo ONLY if you need tires, else you're wasting money.
-Basic maintenance plugs, filters, synthetic fluids. Check your brakes, clean up the hardware, dragging brakes will steal alot from a smaller metro engine.
-Driver habits, route planning, traffic avoidance. Case in point, normal commute with morning traffic is 25.x right now with my Subaru, I worked Christmas eve day and managed 28.2 MPG with the lack of traffic.
-Weight Reduction, If you're drive includes alot of stop/go and points where you need to accelerate weight is not your friend. If you drive alot of continuous highway, weight is more negotiable.

Worst
-Vacuum Gauge Why: Cheap Sunpro $20-30, vacuum tees and hose to splice $5, Gauge pod or in my cause custom pod ~15-30, total $45-60 bucks. UG was $80 shipped and doubles as a $50 code reader, and provide all the data that you need!
-Wheel Skirts Why: Flame if you want, but building these are time consuming, potentially dangerous, and build costs could be high if you want to paint match, quality material, etc. Smooth wheel covers and see where you're at!
-LED Lights, swapping to HID etc. Unless you plan on going alternator-less, there are minimal gains to be had and alot of money to spend.

Hopefully that helps!

Though the 15" tires are 10mm narrower, which is good for aerodynamic reasons, they're also 1.5% smaller in diameter, so you'd do 1.5% more rpm, which is bad.

Lowering the car is a personal choice if you can live with the limited ride height and harsher ride its all good. If your only opting for the springs and not willing to get a full setup it might not be worth it. As for the CAI in the winter a warm air intake might help but raising air temps might hinder that. Colder air is denser and allows for better burning of fuel. If your not on the gas hard it will help. Not all performance mods decrease fuel economy. If you get the CAI I'd sugest a AEM filter as they are dry flow and all you need is soap and water to clean them. If you get a CAI try and get a more free flowing exhaust again when your not hammering the car it will help. Look at your engine as an air pump. The better easier it can breath in and the better it can breath out the better your economy will be.

If you want to lower your rolling resistance you might want to look at 13"-14" light weight narrow rims. Short term gains may not seem that great but long term will be. The benefit of a metro is that 13's would fit just fine. If you can get smaller tires as well you can reduce your rolling resistance.

I think lowering cars and adding air dams made a lot of sense in the '80s (and earlier), when cars were so cobbled up underneath that reducing airflow under the car would guarantee reducing overall aerodynamic drag, but other than the engine compartment, a Metro is pretty smooth on the bottom already, and you can smooth up the engine compartment with ABS or coroplast. I think once you clean up a car's belly belly, you're aren't likely to reduce drag much (if any) by lowering it.

At least, that's my latest theory.

I installed an air dam on my 99 Metro and it acted like an air dam. It blocked air. Of course that meant it kept some air from getting underneath the car, but it didn't really seem to do much to increase my mpg. I had attached a 7" wide PVC panel directly to the bottom of my bumper using 90% corner braces. It was only attached to the bumper and not any framing of the car itself, so the weight of the addition pulled the bumper down in the back enough so that I virtually had an air deflector that was perpendicular to the ground.

Of course my only real world test happened to be driving down the Interstate at 70-76 mph. The result in my case was little to no improvement. I was thinking that my aero mod was in fact an air damn and adding to the amount of wind blocked at the front of my vehicle. Back to the drawing board. You know bullets are rounded for a reason. Using the same 7" PVC and brackets I modified my air damn into an air spoiler. I bent the braces to 45% and ended up having to redo the ends completely because of that. I also attached the braces the part of the inner fender structure of the car. Results - success, I'm now getting 46 - 49 mpg with my 99 Metro.

Final word, make an air spoiler and not an air dam.

I love all of these ideas. Lots to consider. It is going to take awhile to sort out which to do. The $10 air dam sounds good but the spoiler concept sounds great. Keeping budget in mind, I will go cheap first and move on from there. Drifting between the links from this site I have seen higher compression, steel valved heads being recommended. I was wondering if the eco minded folks would think that was a good idea and if so, at what point do you have to put in higher grade fuel? I think it said 9:1 and 10:1 or something like that. I know my 89 Swift GTI had a pretty high compression ratio but was running 86 octane with no issues.

The light wheels sound good to and I am now not leaning towards the skinny tyres. The rolling resistance article was informative. Now I am thinking 165/65 14 on a set of light wheels. The new rig is going to need snows so I will buy those for the steel OEM wheels in the 155/80 13 size.

I also liked the CAI idea. Would a heating pad for the block help here in the Northeast?

Thanks,

Neal

Stainless steel exhaust valves are ALWAYS a good idea-especially on the G10. The higher compression ratio will help with low RPM torque and mean you do not have to push the engine as hard to get the same acceleration. The same holds true for the Metro XFI camshaft or 3 Tech's economy cam. Both raise low RPM cylinder pressure which smooths out the idle and decreases throttle input under normal operating conditions.

As for tires, you could also consider 175 70 13's on your stock rims if you want to try the wider is better idea. They cost about the same as the 155 80 13's and would give you the extra width inexpensively. This is another idea I plan to try on one of my Metros but more for better handling and braking than for fuel economy. No matter what that study says, I have seen the opposite to be true on my truck. 235 60 15's dropped me 1-2 mpg vs the stock 215 65 15. It may well be that the whole reason that the rolling resistance decreases with width is that the load is spread too thinly on narrower tires and going wider in certain circumstances reduces the load. Once you get past that point though it would make it worse. Also, if that is the case, then it stands to reason that wider tires on the front to better support the engine and trans would have the most benefit and the rears should therefore be narrower. However, this is all just speculation on my part as I am struggling to find a logical and mathematical explanation of the data set.

> Every metro of that age is starting to rust around the suspension..

do you suggest a lowering it's a question of time? :D

Neal,
Cheap mods. that are likely to have a high rate of return are always the best place to start IMO. If you need snow tires, you need an engine heater of some kind. It Will help. I personally don't think the wider tires will help you, but that's just my guess.