How much effect do ecomods have around town?

[BLSTIC]

Ok, so I have a Toyota Echo. For those unfamiliar (...how...?) it's an 850kg (not willing to make it any lighter, I use everything installed in the car semi-regularly and I don't want to increase noise), reasonably aero (Cd 0.3) hatch with a moderate sized (1.3-1.5L) 4-valve engine that has sequential injection and variable inlet cam timing. My particular model is a 1.3L manual 3-door with no options except A/C, I even have manual steering, manual mirrors, and locking.

I live in a warm climate, with a typical max speed of around 60km/h, I think I average about 30km/h on my 8km commutes (traffic is fairly light).

I already run LRR tyres at 38psi and employ mild hypermiling techniques (driving with load, high gear fuel cut coasting, minimal braking). I have no desire to run kill switches, but I do key-off at long lights.

Currently I have a faulty thermostat and run the AC during the day so I'm at about 6.0-6.5l/100km around town. I would expect that to improve to 6l/100km regularly once the thermostat is replaced (car still warms up, but at night without a/c on when I get all the lights home it can take about 5-6km).

How much gain would you expect from the various eco-mods given that most of them are aero-based?

[vskid3]

I think your biggest limiter will be not doing a kill switch with how short and low speed your commute is. Aeromods won't help much. You could probably pump up your tires a little more. Technique and driving style will be your money makers. Just because you're doing certain driving techniques doesn't mean you're getting the most out of them or using the right one at the right time.

Do you have any instrumentation? That will help you a lot in determining what's working best for you.

[BLSTIC]

No instrumentation, though I can reliably feel the fuel cut points, so I've just been driving at high loads in the highest gear I can for any given situation. Typically this results in about half to three-quarter throttle with up shifting at 2000-3500 depending on the acceleration needed. Sometime I'm in top gear at 45km/h (I skip gears, can't remember when I last used fourth on the flat)

[Gasoline Fumes]

Things I would try:

Higher tire pressure - maybe try 45 PSI?

Block heater - I use mine all year

Disable the alternator - charge your battery at home every night, maybe add a solar charger

Make sure your brakes have minimal drag

Zero-toe alignment

0w-20 engine oil

Engine-off neutral coasting will be better than high gear fuel cut coasting - compression braking is still braking

[BLSTIC]

I refuse to use pulse & glide with engine off cruise on principle of safety.

I don't think the block heater will help. Certainly the effect of the thermostat will be much more. The normal 'cold' start here occurs somewhere between 20 and 30 degrees Celsius. Once the coolant was already on the gauge, which I later discovered was 55 degrees.

How much gain would you expect to be between the tyre pressure, zero toe, and thinner oil? (Not interested in alternator delete for a wide variety of reason)

Would there be much gain in changing the gear oil? I used to run lightweight engine oil in one of the race-car gearboxes, and one of my other cars ran DXIII from the factory

[MetroMPG]

I would argue that instrumentation would be your biggest potential gain.

People overestimate how efficiently they're driving until presented with the cold hard instantaneous facts.

"I wish I hadn't waited so long to get one" is a common sentiment read around here.

[Fat Charlie]

EOC has as much to do with safety as airport "security" theater does.

If you've got an anchormatic, have leaky brakes or are driving something too big to handle without power steering, your first real step is to fix those problems. If not, EOC is just as safe as everything else you do while driving: you can be safe or unsafe and it's all up to you.

But more important than any technique is good instrumentation.

[twj347]

The easiest and most effective ways to get good mileage at low speed city driving speeds are, more or less in order:
1. Driving style (limiting idling & braking, accelerating properly)
2. Low-RR Tires at highish pressure (Low-RR tire design is more important than pressure.)
3. Keeping heat in the engine (block heater, insulation, grill block)
4. Aero Mods
5. Car Weight Reduction (at least as effective as low-RR tires, but achieving a meaningful reduction in weight is difficult, which is why I place it last)

As for aero mods, you can play around with the Aero Calculator floating around (I'm not allowed to link anything yet) to see how much your aero losses are at the speeds you normally drive at. For a typical car, it might be a 50/50 split of aero/rolling resistance at about 50km/h (ignoring idling, braking), so if you're hitting these speeds or higher, aero mods should help a fair bit.

If you have a way to keep track of your coolant temperatures and radiator fan use accurately, you could install a partial grill block that will help with both aero and warmup. It's the low hanging fruit of aero mods. Even in a warmer climate you probably have more cooling airflow than you need. I blocked over half of my grills and my coolant temps are just fine in 22C ambient temps (haven't tested in higher ambient temps than this yet).

[freebeard]

I don't think the block heater will help.

8 clicks? You need a bigger block heater.

One that heats the transmission too.

[Daschicken]

Originally Posted by BLSTIC

I don't think the block heater will help. Certainly the effect of the thermostat will be much more. The normal 'cold' start here occurs somewhere between 20 and 30 degrees Celsius. Once the coolant was already on the gauge, which I later discovered was 55 degrees.

I'll bet it would. I use my block heater whenever I can, even when it is 80+(27 C) degrees failheit outside. It was 80 this morning and I preheated for just about 2 hours and got the coolant temp up to 110(43C) before starting. If you are doing short trips, a block heater will help a lot!

Originally Posted by BLSTIC

How much gain would you expect to be between the tyre pressure, zero toe, and thinner oil? (Not interested in alternator delete for a wide variety of reason)

I would guess around 4%.

I'll bet your biggest gain would be from not using A/C as much as possible. I have driven in 100 degree(38C) weather without using A/C. I wouldn't recommend it especially since that was a black on black car, but it is doable. Just take your shirt off and bring some cold water to drink.

Originally Posted by BLSTIC

No instrumentation, though I can reliably feel the fuel cut points, so I've just been driving at high loads in the highest gear I can for any given situation. Typically this results in about half to three-quarter throttle with up shifting at 2000-3500 depending on the acceleration needed. Sometime I'm in top gear at 45km/h (I skip gears, can't remember when I last used fourth on the flat)

Make sure you double clutch when skipping gears.