Better Mpg

[circmand]

[QUOTE=twistedsymphony;133308]Theoretically larger rolling diameter will increase highway MPG... the reason is because it changes the ratio of RPMs to tire rotations such that your engine doesn't need to spin as fast to go the same speed.

the down side is added weight which means it takes more energy to build momentum (eg: stop and go city traffic mileage would be worse).


I get that but once you decide on the tire size it seems to me max inflation is the way to go because you get max diameter, minimum rolling resistance and the air dowsnt weigh anything. Or am I missing something?

[Riff Raff]

[QUOTE=circmand;133354]

Theoretically larger rolling diameter will increase highway MPG... the reason is because it changes the ratio of RPMs to tire rotations such that your engine doesn't need to spin as fast to go the same speed.

the down side is added weight which means it takes more energy to build momentum (eg: stop and go city traffic mileage would be worse).


I get that but once you decide on the tire size it seems to me max inflation is the way to go because you get max diameter, minimum rolling resistance and the air dowsnt weigh anything. Or am I missing something?

Basically, the added weight from oversize tires comes from the simple fact that there is more material rubber required to manufacture the bigger tire (more rubber material = more weight).

Remember, it takes "x" amount of energy (gasoline), to move "x" amount of weight (in this case wheel & tire). The ideal solution in gaining maximum MPG with tires & wheels is to run the "tallest" tire that will fit (maximum O.D. = lower engine RPMs for same speed); at the "max PSI" (per sidewall label = least rolling resistance); with the "narrowest" available tread (low section width = less drag); mounted on an all aluminum lightweight wheel like CenterLines (reduced wheel weight = reduced overall weight). Thus, having said that-- an example of the most "economical" tire & wheel combination to mount on the VX is the TOYO - Open Country A/T in 255/70R18 (32.1" O.D., only 10.3" wide, weighs only 41 lbs) and mounted on lightweight aluminum wheels (such as Centerlines).

[twistedsymphony]

you're right that more weight = bad

but there is a difference between weight added to the rotating elements of a vehicle (ie: wheels/tires/driveshaft/flywheel) and just adding weight to the vehicle overall.

obviously keeping the weight down will improve nearly every aspect of the vehicles performance... however when talking about weight in the drive train that weight dramatically effects acceleration... in most vehicles 1lb added to the drive train effects acceleration and deceleration as much as adding 10lbs to the overall vehicle weight. This obviously varies depending on the drive train but the point is that keeping the weight down in the wheels and tires is MORE important to performance/economy than just keeping it down.

That's not even talking about the benefits to handling characteristics. The suspension works better with a lower amount of "unsprung weight" (eg: the amount of weight on the rubbery side of the suspension mechanism).

It's all about momentum... it takes more effort to get heavier tires moving or stopping... be it rotating or bouncing up over a bump in the road....

It's why racers swap out their heavy flywheels and steel drive shafts for light weight aluminum versions... they might only save 50lbs to the overall vehicle weight, it doesn't add any hp or torque but it changes the acceleration characteristics as if they'd dropped nearly 500lbs off the total weight.

[SYNTHETICDARKNESS]

well we got the sens enhancer, got it all sodered on and went down the road for a little tuning, city driving around 45-55 then highways was around 60-70. had it a little to lean though when i first started stalled in my driveway, but after playing for a while i finally got all the controls where they are supposed to be, and no check engine lights saying to lean or anything now, and it runs normal with the hydrogen, but when we shut it off we don't have much power. we are still gonna take it and hook up an air/fuel gauge to make sure everything is reading were it should be for the safe side. i'm just friggen happy it works, wish we could get 100 mpg, but that will probably never happen. all we do have to do now is drive around and test, make sure everything holds good, and if it does, my little vx will have one. as for the tires everyone has there opinions about them, but mine i still think the smaller/lighter the easier, just like having two of the same vehicles one big wheels, and one small going a steady 65 then putting it in neutral and see what one stops first. to me the one with less friction will keep going, because there is less to stop. by the way do they make aluminum driveshafts and flywheels for the vx. likes to get me them if they do.

[taylorRichie]

Please keep me/us posted on your VX install... I'd really like to give it ago... especially if I can write off the reactor (link please)

As for Aluminum Driveshafts, I'm sure any place that makes custom driveshafts for race cars and off road performance can make them for you.

Thanks for keeping us up to date

[SYNTHETICDARKNESS]

that place where we bought ours is www.savefuel.ca, it took a couple weeks before we got it so just depending on how many people are ordering depends on how quick you get everything. we love that it's working so far, so as time goes on i will keep everyone up to date on the progress of everything. as for the flywheel and everything i'll have to see how many fingers i gotta cut off to have them custom made. you can go to the irs website and look at the write offs it's in there somewhere i think with hybrid vehicles or something. this would be easy to install on my vx with my intake could go right behind the drivers side headlight.

[twistedsymphony]

The best place to get a new driveshaft is from these guys: http://shaftmasters.com/

They're known to make really high quality well balanced drive shafts.

DO NOT get one from Drive Shaft Shop... they don't balance their shafts