Master list of 65+ proven mods for increasing MPG

[PaulB2]

Replace the o-ring drive chain with a non-oring version. To do this you should put a chain oiler on the bike to keep it lubed. I cooked one up using a small brass tap and some hose from Ace hardware, pretty sure total cost was less than $15. The hose slowly dripped oil on one side of the sprocket, then from there onto the chain. Of course a non-oring chain is much cheaper than an oring chain, not to mention absorbing less power which is the whole point.

A downside of this mod is that your bike can get a bit oily in the back, but the good news is the chain stays cleaner. Don't even need to take it off and clean it, really.

Finally some people downsize the chain (and sprockets) to the next smaller size. This is a bit risky but if you have a low power bike and are not racing, why not? Do use a top quality chain if you do this.

[j12piprius]

Why aren't side skirts on the list?

65+ Vehicle modifications for better fuel economy - EcoModder.com

[MetroMPG]

Good question! Anybody got A-B-A or a manufacturer reference showing drag reduction benefit? I realize a number of members have made side skirts, but I don't think I've ever seen a testing reference.

I know they've been used in racing applications, but I always thought that might be for downforce, which doesn't always translate to drag reduction.

I also know Aerocivic has a version of skirts, but they're actually more like "pontoons" -- double skirting, the width of the tires.

[Weather Spotter]

I think I did some testing a while back, I'll look up the data and let you know.

[2000mc]

Is the effectiveness of side skirts dependent on how low the air dam is?

[Weather Spotter]

I think i misread the question, is for wheel skirts or side skirts? I have some data on wheel skirts but never did side skirts.

2000mc: yes it would depend on front air dam to some extent.

[cosmick]

Only read the link and the first 2 pages, but sometimes, if your combo can't be geared optimally, camming it with a way-late intake closing can do wonders for MPG as well as for upper-RPM HP. Delaying the cam is contradictory, because while the later exhaust opening will help MPG, it will hurt upper-RPM HP, and that may seem to balance out the gain from the intake closing, but in testing it doesn't work out.
Also, excessive-overlap cams can be taken more advantage of, but they drastically hurt emissions, so I won't explain further. Long story short, you don't want any overlap at 0.075" valve lift. That'll keep the emissions clean enough to pass testing.

[cosmick]

Also, advanced ignition timing can sometimes help output, but the smarter mod is to make the engine give the "extra" output with the existing timing. The best way to do this is a more efficient combustion chamber, including the piston crown, rather than just static compression alone. The only practical way to do this is to start with a more efficient engine. For example, there's no way to make an LT1 as efficient as an LS1, or an LT4 as efficient as an LS6. So admit when you got the wrong engine, take it to the salvage yard, and trade it for something better. One exception to this might be, for example, a Toyota 22R for cheap dual-fuel, even with adding a turbo, rather than something like a 4G63T or an Ecotec. Of course, the 22R can't go to 2200 HP like a max race Ecotec can, but there's no perfection yet, nor on the horizon.

[GDI Tech]

On any port injection or GDI engine equipped vehicle, installing a true air/oil separation system (not the average "catchcan", but something like Elite Engineerings newly released E-2X system for GDI engines) that scrubs, removes, and traps the oil/water/unburnt fuel/and other combustion byproducts from the PCV system, and thus further the intake air charge (especially newer GDI engines) you eliminate most of the detonation caused knock retard, and this allows the engine to operate at optimum spark timing advance. Thus more power, cleaner burn, and better fuel economy (1-3 MPG average for full size vehicles, more on compacts). This also eliminates most of the coking, or deposit build up on the backsides of the intake valves that over time results in gradual reduction in fuel economy, power, and an increase in emissions as the valve deposits build wearing the valve guide prematurely as well as other issues.

Here are examples:
(Note, I can't post images yet...will follow up later with them)

And no, top tier fuels and additives added to the fuel tank can do nothing to prevent or help this as fuel no longer showers the intake valves keeping them clean and cool as port injection:


Today's engine fuel never touches the backsides of the valves so as all gasoline comes from the same distribution, paying more for a "top tier" does absolutely nothing now days as it never touches the valves. So waste of $ big time. Also, the argument that the injectors need it is also unfounded as now the fuel is introduced at 2000-3000 PSI basically "pressure washing" the insides and the tips so we rarely see deposits clogging them ever form unlike port injection that operated at 45-55 PSI.

Also, if you use a solvent based upper induction cleaning, you risk damage to the cylinder walls and pistons as well as the catalytic converter due to the very hard particles that are breaking loose and smaller ones forced between the piston and cylinder walls, causing scouring, or scratches. Then if you have a turbo equipped engine these hard particles & chunks are impacting the exhaust side of the turbo and damaging the leading edges of the turbine blades.

Much misinformation out there, and no automakers are admitting any of this, but if you have a GDI engine vehicle, you really need to learn all there is involved with the care of these unlike a port injection engine that could go several hundred thousand miles and see zero deposits on the intake valves.

[Formula413]

Originally Posted by cosmick

there's no way to make an LT1 as efficient as an LS1, or an LT4 as efficient as an LS6. So admit when you got the wrong engine, take it to the salvage yard, and trade it for something better.

I will never give up my LT1!

Originally Posted by GDI Tech

Much misinformation out there, and no automakers are admitting any of this, but if you have a GDI engine vehicle, you really need to learn all there is involved with the care of these unlike a port injection engine that could go several hundred thousand miles and see zero deposits on the intake valves.

I never thought of that, very interesting. I'll have to give this more consideration and research. I'm leaning towards a Mazda3 with the Skyactive direct injection engine for my next car.