Increase MPG

[mezrein]

Hey guys, Im running an all stock 93 Navajo, v6, 5 speed stick with 206k miles on it and Im getting about 20mpg freeway. Wondering if there is anything I can change on the cheap to get an increase to maybe 22mpg or better. Running 87 octane right now. Again, all stock.


Thanks all!

 

[Maniak]

That pretty good mileage for a 4.0 OHV motor. There aren't really any "mods" you can do to increase your mileage let alone be cost effective.

Really all you can do it keep it tune (plugs/wires/air/fuel filters etc), use synthetic fluids everywhere you can (diff, trans, engine etc). Getting a motorvac run on the fuel system (cleans the injectors) might be worth doing with that many miles since a better atomized fuel will burn better.

~Mark

 

[mezrein]

That pretty good mileage for a 4.0 OHV motor. There aren't really any "mods" you can do to increase your mileage let alone be cost effective.

Really all you can do it keep it tune (plugs/wires/air/fuel filters etc), use synthetic fluids everywhere you can (diff, trans, engine etc). Getting a motorvac run on the fuel system (cleans the injectors) might be worth doing with that many miles since a better atomized fuel will burn better.

~Mark

Where can I get a motorvac run done? I looked up motorvac and it looks like a HVAC system cleaner?

 

[Maniak]

Where can I get a motorvac run done? I looked up motorvac and it looks like a HVAC system cleaner?

You are going to need to find a shop to do it. I believe it's officially called a motorvac carbon clean service.

Basically they run your vehicle on a mixture of cleaner and a little fuel and the machine kinda acts like the fuel pump on your vehicle.

The cleaner is really strong so you can't just toss it in the tank.

If you have always run really good fuel (chevron/shell etc) from good stations (not old fuel with dirt/water) then the motorvac may not help but for < $100 you can get the injectors cleaned (as well as they can do it on the vehicle).

~Mark

 

[mezrein]

You are going to need to find a shop to do it. I believe it's officially called a motorvac carbon clean service.

Basically they run your vehicle on a mixture of cleaner and a little fuel and the machine kinda acts like the fuel pump on your vehicle.

The cleaner is really strong so you can't just toss it in the tank.

If you have always run really good fuel (chevron/shell etc) from good stations (not old fuel with dirt/water) then the motorvac may not help but for < $100 you can get the injectors cleaned (as well as they can do it on the vehicle).

~Mark

Ahh ok, excellent. Think Ill be finding a shop. I tend to run Albertsons or Fred Meyer gas, I use to use nothing but 76 Gas, but been going for convenience lately.

 

[natenkiki2004]

If it's $100 to clean the injectors, I'd opt to replace them with a set of 4-hole refurbished ones off of eBay like this:
http://www.ebay.com/itm/2-Yr-Warran...er-4-0L-91-95-Fuel-Injector-Set-/131547547457

I'm still doing MPG tests with my set but I notice easier starting and have not had a warm-start issue like I did with the old injectors.

 

[mezrein]

If it's $100 to clean the injectors, I'd opt to replace them with a set of 4-hole refurbished ones off of eBay like this:
http://www.ebay.com/itm/2-Yr-Warran...er-4-0L-91-95-Fuel-Injector-Set-/131547547457

I'm still doing MPG tests with my set but I notice easier starting and have not had a warm-start issue like I did with the old injectors.

Wow those are cheap. Being non-mechanically inclined how hard is it to replace injectors? Also, do these work with the Navajo's?

*Update*
Looking at the list of covered models they only support up the 92 Navajo.

 

[FR-425]

EPA rating is 15 & 19 for the standard trans and 14 - 18 for automatic.

You're not going to get better fuel econ.

Save your money. It's a witch hunt....

 

[natenkiki2004]

Wow those are cheap. Being non-mechanically inclined how hard is it to replace injectors? Also, do these work with the Navajo's?

*Update*
Looking at the list of covered models they only support up the 92 Navajo.

It's all for the 4.0 OHV. Technically, those injectors are out of a Mustang. It doesn't matter what vehicle they are from/for, what matters is connector, physical size and flow rate. All 3 values are identical to the ones that came on the 4.0 OHV's. If you want to be sure, message the seller. He's very friendly and helpful.

As far as replacing, it's not terrible. Upper intake plenum has to come off then the fuel rail. You need (I think) an E7 torx socket, the external kind. Aside from that, it's just regular metric sockets. A few extensions would help. Take a look at my signature and click on the 4-hole Mustang Injectors link.

As it's been said already, these OHV's are hungry and with a boxy design, old computer system and weight... you're not going to see high MPG. I don't know if these injectors help with MPG yet. About the highest I ever got was 14.1 which is probably 30% highway, 20% city and 50% rural roads including gravel.

 

[mezrein]

EPA rating is 15 & 19 for the standard trans and 14 - 18 for automatic.

You're not going to get better fuel econ.

Save your money. It's a witch hunt....

Ya Ive seen the epa rating for it, just always been the type that believes you can always squeeze more out of something, more performance, more mpg, more more more,

 

[Watchman]

Hey Nate - I checked Ebay on compatibility for these injectors- where you put in your vehicle description - and it indicated that these injectors were not compatible with my 93 EX. Is there something wrong here ?

 

[Maniak]

IIRC 1993 is when they switched from batch file to SFI on the Explorers but I don't see that as being a reason why they wouldn't work.

I check a few selling sites on the 'net and they were showing the same injector part # for 1992 and 1994 (e.g. Bostech MP2093)

~Mark

 

[vq5speed]

I suppose if you tried cutting weight like strip all carpeting and rear seats out don't carry a spare tire. Lower the suspension take off the roof rack for better aero dynamics. Add front spoiler put lighter rims on you might be able to gain some MPG doing that...

 

[natenkiki2004]

Hey Nate - I checked Ebay on compatibility for these injectors- where you put in your vehicle description - and it indicated that these injectors were not compatible with my 93 EX. Is there something wrong here ?

I was concerned about that too but I did research and asked around... it doesn't matter. Sequential vs batch, the computer doesn't care what model of injector you have as long as the flow rate is the same and it is. If you think about it, 4.0L is 4.0L. It will always suck the same amount of air in and thus will need the same amount of fuel. Regardless of OHV/SOHC and year. A more important thing to think about is the physical size of the injectors and connector, both of which are identical in that eBay listing. The injectors in the listing are basically a newer revision of the ones that Ford stuck in our first gens. I'm pretty sure they're actually the newest revision that will physically fit without modification.

 

[mezrein]

I suppose if you tried cutting weight like strip all carpeting and rear seats out don't carry a spare tire. Lower the suspension take off the roof rack for better aero dynamics. Add front spoiler put lighter rims on you might be able to gain some MPG doing that...

Well already took the roof rack off. Never used it anyway. The few times a year something does go on the roof it just sits on the runners anyway. Might take out the spare tire, would love getting better rims, front spoiler? And suspension is already lower than the most explorers.

 

[vq5speed]

I was concerned about that too but I did research and asked around... it doesn't matter. Sequential vs batch, the computer doesn't care what model of injector you have as long as the flow rate is the same and it is. If you think about it, 4.0L is 4.0L.

I did some research on this 4 hole injectors too. This Bosch 19# injector we use is used on lots of other cars even V8. This 4 hole injector used on the V8 I have seen sets of 8 injectors for less then a set of 6 for the 4.0L engine. I just looked on ebay you can buy set of 6 now for $85.00. the price has dropped they were like $99 a set

 

[Gilbert G. Jr.]

I consciously do a foot reset on the pedal. Once you are up to speed at the speed limit you can reset your foot with light pressure to maintain speed. Of course there is many variables to make this work but as long as its always in practice I always squeeze the most out of my tank.

 

[natenkiki2004]

I did some research on this 4 hole injectors too. This Bosch 19# injector we use is used on lots of other cars even V8. This 4 hole injector used on the V8 I have seen sets of 8 injectors for less then a set of 6 for the 4.0L engine. I just looked on ebay you can buy set of 6 now for $85.00. the price has dropped they were like $99 a set

Yea, it's a pretty popular style. I think I paid $99.00 for my set, at $85 it's a no-brainer. Even if your stock factory injectors are working properly, you'll benefit from a better atomization from the 4-hole design. How much of an improvement and how long will it take in mileage to cover the cost... that's the big question.

 

[vq5speed]

I think its worth it. As much as I like doing my own work and seriously thought about just rebuilding my own injectors. The O-ring kit is cheap but the time spent to take apart each one and clean them. Just buying them already cleaned rebuilt and performance matched I felt buying them rebuilt was the better idea. When I replaced mine I was having an issue. I thought that maybe I had a clogged injectors. Turned out it didn't solve my issue but I wanted to replace them with rebuilt ones anyways.

 

[trozei123]

That pretty good mileage for a 4.0 OHV motor. There aren't really any "mods" you can do to increase your mileage let alone be cost effective.

Really all you can do it keep it tune (plugs/wires/air/fuel filters etc), use synthetic fluids everywhere you can (diff, trans, engine etc). Getting a motorvac run on the fuel system (cleans the injectors) might be worth doing with that many miles since a better atomized fuel will burn better.

~Mark

What do synthetic fluids do differently from regular? Are they worth the extra cost for a 92 ex with 240k on it?