Your thoughts/experiences with desmogging..

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Sep 14, 2009
Medford, Oregon.
With the aim of increasing my MPG on my '62 what are your thoughts on reducing/eliminating smog equipment and it's effects on the engine's performance?? Anyone have something good to report along these lines? I've read the Desmog threads in the forums and it seems to be a mixed bag of yes and nos. My muffler is new but cats are probably stock units. How about whacking those off and/or combining my dual exhaust tubes into one? Replacing the air/smog pump with an air compressor or second alternator or just eliminating it? I'm not interested in improving performance, just squeezing more miles out of every tank of gas.;)
i would think you still need to pass DEQ dont you?

In the Medford area vehicles 20 years AND NEWER must pass a smog inspection. Mine is a 1989 so I'm assuming no emissions testing is needed. How about the cats Aric?? Should I start by removing them(Jesse)? The O2 sensors are upstream of both cats.
Weight..... you need to get the sawsall out! :D Get rid of the body!!!! and any of the frame that you don't really need...... :cheers:

It's the body style of the 60's that I like so much. The 80's and newer- you can have them. They are too "round" for me. ;)
You no longer have to smog it so deq isn't a concern. It is illegal to remove cats but I've never had a problem with cops checking and I don't currently run one on my Mr2. Unless they are clogged I doubt you would see any gains in mpg although you could improve power some. The biggest improvements to mpg usually come from a properly tuned vehicle. O2 sensor must be clean, all ignition components must be in perfect shape, cats not clogged... then it comes down to weight and drag... keep the truck empty of stuff, remove anything that would hurt aerodynamics(roofrack), run narrow and properly inflated non-aggressive tires, aluminum rims help reduce rotating weight. Most of all drive it like a 90 year old lady! I've made some impressive mpg tanks just by being ocd about good driving habits which is part of the reason I drive a stick because I kick it into neutral every chance I get. I averaged 31mpg in my wife's Mercedes going to kfalls and back even though her car was only rated 25mpg hwy. Drive slow up the hills and coast down them!
As far as the smog equipment is concerned there is some drag from the smog pump but if you're replacing it with something else you won't gain anything...besides that it's just a bunch of vacuum lines and valves. I'd eliminate it just for simplicity but better mileage probably won't come of it.
OK, so basically don't mess with it and save money for a TB injected V-8 and OD tranny. Since that's a BS pipedream I will just stop worrying about smog stuff and get a tune-up instead. Truck is 5900 lb. empty. Roofrack?? Bobby likes to sleep up there. I will wash and wax it so it is "more slippery". :p
Its a land cruiser not prius


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