Certain 4cyl cars that get bad mileage..

[cRiPpLe_rOoStEr]

By jurisdiction, I meant other countries with different rules. Well, there might be many other loopholes that could be not exactly the best way to circumvent emission laws...

[jcp123]

Small volume builders now have an exemption to many of the safety and smog laws. This is how you get new-build Superformance Ford GT40 replicas and the like.

Emissions testing is hardly uniform though. In Texas, for instance, only counties above a certain population (500k, I believe?) administer emissions testing. By contrast, California conducts emissions testing across the board, and to stricter standards than Federal mandates. I believe much of the Northeast has followed suit.

More to the point...4-cylinder doesn't necessarily equate to fuel economy. Nor is there a perfectly straight correlation with other factors such as engine displacement. Gearing, mechanical condition, driving style, etc. all affect the real-world fuel economy of a vehicle.

[Hersbird]

Originally Posted by JSH

In the USA engine swaps are illegal on any vehicle made in the last 40 years or so but it is not enforced by the federal government. Instead enforcement is at the state level and the rules vary. Where I live vehicles are inspected every 2 years so I would have to swap the original engine back in to pass inspection. (Some people actually do this!)

Actually a well done swap wouldn't even get flagged at the strictest inspection. The average smog check tech is just plugging things in to a computer and doing a once over visual. Back in the day before computers there was a fun thing racers did to make something look as simple and factory as possible while actually making serious horsepower. A 283 small block might actually be over 500 ci. A nitrous system plumbed underneath the intake manifold. Factory parts bored and honed to make them as good or better than aftermarket exhaust and intakes, etc. The same can and probably is done today. If I want a 6.7 Cummins in my 5.9 I can make it look almost identical outside and my factory computer will control it without codes. I bet the average smog check guy wouldn't notice even swapping a Honda 4 cylinder for say a Toyota as long as the computer isn't throwing codes. Most people won't want to spend the time to make things look factory and there really isnt much of an advantage to try but it certainly possible.

[cRiPpLe_rOoStEr]

Originally Posted by Hersbird

Actually a well done swap wouldn't even get flagged at the strictest inspection. The average smog check tech is just plugging things in to a computer and doing a once over visual.

Well, now that Cummins is offering its R2.8 as a crate engine, and it's emissions-certified (even though it's not compliant to current standards, at least not yet), it is already OBD2-compliant, so it may seem like engine swaps are not "illegal" at all back there.

[PressEnter[]]

Not sure where the conversation is going, but the reason I got into hypermiling was because I realized I was getting barely 22 mpg in my '03 Mazda Protege5 and looked to see what I could do to improve that. I did squeak a couple of 30 mpg tanks after that, but as it turns out, when the EPA updated the ratings, the 2.0L Proteges only got 25 mpg combined, which I find appalling for a car that didn't even have ABS and only weighed 2700 lbs.

[redpoint5]

Originally Posted by PressEnter[]

Not sure where the conversation is going, but the reason I got into hypermiling was because I realized I was getting barely 22 mpg in my '03 Mazda Protege5 and looked to see what I could do to improve that. I did squeak a couple of 30 mpg tanks after that, but as it turns out, when the EPA updated the ratings, the 2.0L Proteges only got 25 mpg combined, which I find appalling for a car that didn't even have ABS and only weighed 2700 lbs.

That's pretty terrible for a small vehicle built after 2000. Was the gearing too short?

[PressEnter[]]

Originally Posted by redpoint5

That's pretty terrible for a small vehicle built after 2000. Was the gearing too short?

That was an issue on the highway, but I don't know why it was so inefficient overall.

[WyrTwister]

To give you something to compare to ;

2015 Chevy Sonic 1.8l automatic - in town - 22 - 26 MPG , depending on A/C use or not - highway , up to 35 mpg

2006 Buick Lacrosse 3.8l automatic - in town around 17 mpg , depending on A/C use or not - highway , up to 27 mpg

[triangles]

Engine swaps in the US are legal. What is not legal is to put an older engine with looser emission standards in a newer car with more strict standards. Regardless even this is rarely enforced.

Also the trucking industry somehow found a loophole in the EPA regulations because they can put an old rebuilt engine into a newly manufactured truck that never had an engine in it. This "new" truck is only subject to the emission requirements of it's 30 year old engine.

[19bonestock88]

I don’t know why they don’t make “glider” chassis for regular size cars/light trucks... would allow a consumer to update to a newer body style but keep whatever powertrain they want...