Simply picking a smaller engine may not lead to an actual improvement to fuel-efficiency
 

Some of those Chinese mini trucks, for example, are usually fitted with copies of the Suzuki-designed G13A engine, and their fuel consumption is in pair with larger vehicles, since some lower gearing is required in order to cope with a similar payload.
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Too small is as bad as too big. Engine needs to be sized correctly for it's intended use.

That thing would probably do well with one of the various 1.4L turbo engines out there. Turbo would allow for taller gearing and bigger pay load, while maintaining small displacement efficiency on light load.

It’s not the engine. It’s the operator. Every vehicle needs a plan. Use it incorrectly and be disappointed.

Gearing & transmission covers engine “deficiencies”. That is where it happens.

Nominal fuel burn can be outweighed by reliability & longevity.

FE is ONLY a use marker.

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To an extent. I remember some years ago reading about a very proud Chevy Suburban owner who rolled past 500k miles. I recall calculating the fuel costs at being over $150,000. Now mind you, a Suburban has more utility than a Metro, but those fuel costs will also buy a lot of used cars plus the gas to take them all to 500k. I could buy 8 Insights for instance, and put 250k more miles on each of them for the price in fuel alone of taking the Suburban that far.

Reliability has a dollar value, but it's not the ultimate and only value

POTENTIAL utility. When it is used as a solo commuter it has the same utility as a Metro or even a bicycle depending on trip distance.

Similar dynamic with the "too small engine" scenario: If the vehicle is subjected to "overload" (operating on the far side of it's BSFC sweet spot) 100% of the time then yes it'll burn more fuel vs an engine in it's BSFC sweet spot under identical conditions OR it will be capable of superior fuel economy those times it's not under max payload OR if the operator doesn't simply go WOT the whole time.

Indeed. So having both a Metro and a Suburban in the driveway, or even just renting the larger vehicle when necessary if it's infrequent enough, ends up being far more economical than having a reliable guzzler.

As said, it’s the operator.

Not everyone is a commuter. The number of scenarios where a non-FE vehicle IS the right choice is only limited by imagination. Or the tax code.

FE is a ONLY a marker of sound operating practice. No decline (10%) means all is good for that plan.

The reason for records is to project costs based on use data. The AVERAGE MPG over a calendar year against fuel price.

Given that 99.97% won’t ever change their driving habits as part of a (business) ownership plan (that includes this crowd: not combining trips, etc, to dead-minimize cold starts) is almost only ever set against present conditions.

In other words, the car is accessory to all else. Address, “lifestyle” (I just love that bull**** term), etc.

Economy would place Transportation near the top given its cost.

But it’s address first. And “homes” that also place transportation last.

Those two are where all the money lays. The dollars.

The fractions of a cent of fuel cost is playing with tiddly-winks.

The 22R Toyota is a dog. Not fuel efficient. But it lasted. For guys who couldn’t change a spark plug or a fuel filter. Reliability/Longevity is its own merit.

I’d bring up IH truck motors, but nearly everyone who’d bought them new has already passed on. Same for the Big Three “Industrial” motors. The jobs they were put to were about proper gearing use. FE was abysmal.

A V8 318-3 would last. A V8 440-3 would as well, and more easily move those lighter loads. But was more expensive to build, buy, and maintain.

Daily fuel costs are against IRS-deductible miles. Neither was terribly far from the other in this.

I can think of countless examples of a small-block car just BARELY being more fuel efficient than the big block offering WHERE the big block owner was genuinely motivated. Average fuel cost over a year. (Rarely is this for a business).

“Business” is usually the cheapest means to net. The luxury of very exact specifications comes in long later.


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The problem with the G13 is it's mounted longitudinally with a crappy drivetrain.

Even with the bigger G16, fuel economy sucks for those Suzuki-style vans.

The economy drag of front-engine RWD and associated hardware becomes proportionately worse the smaller the engine gets.

That said, I've driven small diesel Suzuki Carry vans that get 30 km/l. I'm betting they'd get much better, however, if they were FWD.

RWD might not be the problem. You know, they're geared quite too low in order to enable them to climb steep hills and rice fields with an overload which predictably kills fuel economy...


Maybe if it had the same driveline of the former Suzuki Celerio Diesel which used the same engine mounted transversely in FWD?

While that part is true, the losses are still a big deal. We dyno'd one. The drivetrain losses given the quoted power were hilariously high.

Most likely. Though apparently, the Celerio gets low gearing also.

It has (or at least seems to have) taller tyres, which basically render the final drive ratio higher.