MPG Testing AR-5 + 93 Octane

[tom4bren]

Thanks Dad, I refrained from holding the clutch in on the way home and I think I heard a small gasp of relief from the bearing. Seriously though, don't you just offset whatever savings you gain on the pilot bearing with wear on the clutch and synchros from having to shift and re-engage again? It certainly doesn't feel as smooth to shift in and out of gear as it does to hold the pedal down and let it go.

Yer welcome Son

It depends on too many factors to give you a straight answer. On some cars you can slip it out of gear without pushing in the clutch (can't on my Amigo though so I assume can't on your VX either). Considering how much I have to 'row' through traffic, I don't see how an extra shift now & then to take advantage of coasting will make an appreciable difference on clutch longevity. On a bad traffic day, I'd conservatively estimate that I push in the clutch 1000 times on my commute home. It also depends on your driving habits like how much you feather the clutch when shifting & stuff. Ideally each shift is done at a constant speed & acceleration/deceleration is done after the shift - that gives you the smoothest shift and will make your clutch last the longest.

[Med!c]

I get about 20mpg highway my self on my 2000 trooper 5 speed. I dont think you'd need the 91 octane since I get my mpg using regular gas with whatever ethanol content they have now days. I've been wanting to give my mpg a test with ethanol free gas a place near GWNF has.

[eternal21]

I'm most excited about the full size spare on board, as I'll be mounting mine on the rear in the near future, and I was worried about how it might affect gas mileage.

[tom4bren]

I'm most excited about the full size spare on board, as I'll be mounting mine on the rear in the near future, and I was worried about how it might affect gas mileage.

Probably not at all. I didn't notice any difference whenever I stopped carrying mine. The roof however is an entirely different matter.

[eternal21]

Probably not at all. I didn't notice any difference whenever I stopped carrying mine. The roof however is an entirely different matter.

I can imagine. Roof mount = wind resistance FTL.

[Etfren]

I get around 17 MPG in town with mine (5-spd and 35's) but just got 19 MPG while driving out to the coast last weekend. I also got around 18-20 on the drive out to Moab, with cruising speeds around 75 the whole way. Mileage depended on if I was driving across the flat bits of Idaho or through the hills in Oregon.

[vt_maverick]

Results from the way home...





(Gas is like $0.40 cheaper per gallon in VA. )



Calculated MPG was 20.45 after adjusting for tire size. Keep in mind that we live in the mountains of Virginia, so that's without the benefit of the additional downhill time you'd have driving further east.

[vt_maverick]

Also for anyone interested in oil consumption I burned a full quart on the way to Dayton but barely half a quart on the way back.

[vt_maverick]

I get around 17 MPG in town with mine (5-spd and 35's) but just got 19 MPG while driving out to the coast last weekend. I also got around 18-20 on the drive out to Moab, with cruising speeds around 75 the whole way. Mileage depended on if I was driving across the flat bits of Idaho or through the hills in Oregon.

Now that is damn impressive.

[Marlin]

I will say that the ethanol content makes a huge difference pending the vehicle and loading. WHen I towed the VX out to Moab behind my expedition, I went from 9-10mpg with ethanol to 12-14 once I hit WY I think, maybe KS. That included all the mountains and everything. Our trucks were never designed with ethanol in mind, so it may make a difference.

[89Vette]

Our trucks were never designed with ethanol in mind, so it may make a difference.

From everything I learned about computer operation and tuning, ethanol is usable in any ODB2 vehicle (including VX). The injectors and fuel lines haven't been reported as degrading due to ethanol content either.

Though I originally had thought the difference was closer to 10%, materials I've read more recently suggest 5% increase in fuel usage should be expected when running E10 vs gasoline. Even IF closer to 10%, pure gasoline cost THAT much more too -- so there's no gain even if you can find/pay for it. Though it's nice to post numbers, it still hits the pocketbook about the same.

Finally, the O2 sensor is the primary component that IS designed to compensate for differences in fuels. It's "delta" changes with the change in fuel. It sees the need for more fuel and asks the ECM to provide it. Injector pulsewidth (PW) increases with the need for more fuel to get the burn back to a delta of "1". Where some talk about changing AFR from 14.7 to 14.1 that's just a starting point for most ECMs. Ultimately, the ECM is constantly monitoring for any changes in fuel -- whether crappy or E5, E10, or E15. It "knows" how to react by monitoring the O2 sensor.

Because there are limits, it takes a special system to handle something more extreme like E85. ECMs can only compensate so much. In the case of 1st generation ODB1 computers, the tolerance was +/-15%, giving a total "spread" of about 30%. OBD2 computers might be even wider.

I think I heard where they finally are realizing making fuel from corn is/was a bad idea. Seems I heard at least one state was considering LOWERING ethanol content. But, I didn't hear that first hand.

[vt_maverick]

If you're driving a VX I doubt you're too concerned about pinching pennies on gas to begin with; personally I just like seeing how far I can stretch my tank.

[JAMAS]

Also for anyone interested in oil consumption I burned a full quart on the way to Dayton but barely half a quart on the way back.

...Darn....you were in Dayton.....

...you could have stopped by on your way down or up .....

...west chester is about 20-30 miles south of Dayton

[vt_maverick]

Doh... sorry about that!