Plug Change

[chieftmc]

Originally Posted by Fredvon4

The normal 02 sensor is a low tech and low cost device with a 0 to 1 volt range of change...and the individual points between 0 and 1 volt are few so it is a course calibrated device

Some years back Bosch developed a Wide Band sensor that out puts 0 to 5 volts and because there are more discrete steps from rich to lean it is a finer or closer calibrated unit

With more precise data, the ECU can be programed to have many more steps in it's mapping curve.. thus being more precise in it how it manages the ignition timing, valve phasing (we have variable intake valves), and fuel injector timing and pulse width

The motors, with the more expensive sensors can stay longer in the best optimum fuel air ratios to maximize power and fuel efficiency

The second "down stream" O2 sensor is ALWAYS part of the health check for the catalytic converter and almost always a narrow band lower cost sensor

Once again I thank you sir! You are a gentleman and a scholar . It's great the way we get to learn new things everyday . By the time I get my I'll be as "smart" as a smart tech or better !

[artificial]

smart

[xcrew229x]

I await Fred's technical analysis of procreation in general, and debauchery in particular. Poor little blue car....... Ms Farnsworth.......

[bumblebee08]

Originally Posted by JRyan

That's the shortest plug change interval I have seen in modern cars.

A little research on the web results in this cross-reference page:
DENSO SPARK PLUGS

It appears that the car comes with the low end basic plug from Denso (not surprised). When it comes time to change mine, it appears moving up to the IXU22, their Iridium Power line, or VXU22 - their Tough line. They can yield minimal performance and fuel econ improvement, but most importantly, longer plug life (5x normal plug) in the case of the Tough line.
DENSO SPARK PLUGS - Basic Knowledge

The IXU22 seems to be $12 a piece. VXU22 is hard to find, the only place I found in Japan is about $16 a piece.

Perhaps someone will know a better place to find Denso plugs. JCWhitney is a dealer, but their Denso catalog does not list smart in it.

JRyan, you need to double check your cross reference, Denso does not currenetly show an Iridium cross for the XU22HDR9 plug the smart uses. If you check the specs, the IXU22 and VXU22 are both 7.5mm shorter reach(19mm vs. 26.5mm). If you install them is a smart, the exposed threads are going to act like glow plugs, and your going to have major detonation issues. Good try, and they are close, but I just didn't want anyone buying $40 worth of plugs they can't use.

[Old smart]

I have a sneaky feeling that the Denso XU22HDR9 plug and the Mitsu 3B20/3B21 engines are unique to each other. BTW, the "22" heat spec of the XU22HDR9 is the third hottest in the range behind "16s" and "20s."

NGK does not make any plug for the 451 either, only plugs for the 450 gassers (LKR8A).

[bumblebee08]

Old smart, I think your onto something, I've been doing a lot of research, and cannot find a cross for the Denso plug from any other manufacture. I did find what appears to be a cross from Denso to an Iridium plug, their P/N SXU22HDR8. Only difference is a .8mm gap vs. a .9mm gap, but that should be adjustable. I haven't tried to locate anyone who may have these yet, but the plug specs match. I would really like to locate either a platinum or Iridium plug for longer life.

[piglith]

I wonder if there is a cross reference to these plugs

Halo Spark Plug - Increase Gas Mileage & Save Gas

[smarticus]

Looks awfully closed or shrouded to me, that's not a good design. The arc needs to be as much in the open as possible and should be as near to a straight line of sight open to the intake valves as can be. I'd bet these would actually produce less power and economy than the stock plugs.

[bradgarbus]

I am working on getting more information on the engine oil intervals etc. I am going directly to Mitsubishi using a Japanese contact. I will let everyone know what I learn.

So far I can tell you in their cars they recommend changing the oil every 7500 miles no more than that. In heavy stop and go they informed me they suggest no more than 5000 miles at most.

I find it curious that the smart has one of their smallest engines yet it is suggested by smart to do a 10,000 mile oil change... (I smell something fishy)

My gut is telling me to do oil changes every 5000 at most on the smart.

I will share if I learn anything new. Translation from Japanese to English and back can be a challenge. Something just doesn't feel right about the intervals that smart suggests.

[xcrew229x]

Originally Posted by bradgarbus

I am working on getting more information on the engine oil intervals etc. I am going directly to Mitsubishi using a Japanese contact. I will let everyone know what I learn.

So far I can tell you in their cars they recommend changing the oil every 7500 miles no more than that. In heavy stop and go they informed me they suggest no more than 5000 miles at most.

I find it curious that the smart has one of their smallest engines yet it is suggested by smart to do a 10,000 mile oil change... (I smell something fishy)

My gut is telling me to do oil changes every 5000 at most on the smart.

I will share if I learn anything new. Translation from Japanese to English and back can be a challenge. Something just doesn't feel right about the intervals that smart suggests.

That's the fleece filter and synthetic oil talking, 10000 miles. That is simply an MB thing.