3b 60 - only 18mpg? - Warning - math content... (1 Viewer)

MrMoMo

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Ok, now I'm starting to get really worried...

last fill up I put in 66L. Drove 520Km then put in 69L - safe to say I used roughly 69L to drive that 520km

520/66 = 7.879 km/L
100/7.879 = 12.7 L/100 km

OR

66/520*100 = 12.7L/100km


12.7/3.78 = 3.36 G/100 km
or 3.36G/62.5Mi


62.5/3.36 = 18.6MPG

31 series tires = 5% error, 18.6 *1.05 = 19.5 (ok, so it's not 18mpg)

Now, My 8Cyl, 7.3L F350 with 10 times the balls can get 18Mpg, WHY am I only getting this out of the little wimpy 3B?

I'm keeping it under 2200RPM, most driving is on the highway, I'm not lugging the engine.... I don't have a massive fuel leak, and I'm not towing. Where is it all going? - PLEASE help!
**EDIT** - Oh, there is no black smoke either.... incase someone thought I might be overfuelling **
 
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mac

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Winter diesel returns less fuel economy. That's one possibility. Do a couple of more tanks and see if it's consistent.

How's your brake system- calipers and fluid cleanliness? Brake drag unnoticed can suck the fuel.
 
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The 66 litres is irrelevant to the working out as you used 69 litre to do 520klms because thats how much you had to replace.;)

I see it as 69 litres divided by 5.2(520)=13.269 or 13.2/100

I worked that out to be 17.8 mpg.
 

brownbear

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ok do one test with the 7.3 ford. It's winter man. I think you're getting fine MPG.

But that said make sure your tires have proper inflation, no brakes are dragging, etc....
 

MrMoMo

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Interesting and usefull thoughts...

mac:
I'll check for brake drag - I don't feel any (rolls down the driveway) but I'll jack it up and check.

roscoFJ73:
You're right - I used the wrong number - I meant to use 69L (duh). The only relavence to 66 was that I knew I used aproximately the same amount each time I filled up, so I knew my "empty" and "full" marks were the same tank to tank (I know it's 90L, it's just where I generally fill up)

Diescipel:
I hope not!! (230K Km) What other signs would point towards needing a re-build? (not smoking)

Brownbear:
I'll check the tires (new ones going on soon!) - I'm sure last winter I got better milage than this - I would figure I should be hitting at least 600km on 69L (~20MPG)

Dougal:
I'd tell you I just cleaned it, but then I'd get MOBBED because you would all know I'm still running the K&N that came in it (Ouch, ow! stop throwing rocks at me!!)

watrob:
Uh.... you payin' ? !! Fuel filter was done a few weeks ago, Air cleaner is clean. I don't even want to start thinking about how much an injector pump/injector service would cost me. :-(

Thanks for the help! - see my free give away!
https://forum.ih8mud.com/chit-chat-section/194925-mrmomos-holiday-give-away.html#post2860458
 

brownbear

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dump some cetane booster in there and see how much your mpg goes up. Although the cost of the booster plus the fuel for the extra mile or so might cancel out each other. But it might make it more like summer fuel.
 
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You know you have to do alittle service every now and then, you just cannot keep puting fuel in one and expect it to run forever.

I would take the injectors out and get them cleaned, also diesel injector pumps do wear out and need rebuilds.

If your lost 5 miles per gal it would not take long to get your money back after the service costs. You could get a compression test done as well if your getting the injectors done.

I know where your coming from about the costs but at least with a diesel your overall service costs are half that of a petrol motor and you get better MPG than a petrol does as well.

Rob
 
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Before you start throwing money at things that may not need it (injectors, pump etc), it'd be a good idea to try to nail down the problem exactly.
While it'd be nice to have rebuilt injectors and pump, if you can't isolate the problem beforehand it may not help at all.

Do you have an EGT gauge? I'm guessing not if it's non-turbo but if you do then has your cruise reading changed recently?
Do you have any local hills that you've previously benchmarked your truck up that you can compare against?

Is it harder to start than normal?
Does it blow smoke? What colour, more or less than usual?

I recently got my injectors done after probably 100,000km. No change in fuel economy, power or smoke. But it does start quicker.
 
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There was no reference to the type of driving (short trips, stop and go, hiway, etc). When I'm starting and shutting down just after achieving running temp in the winter, my numbers aren't much different than your results. You may want to investigate the running temp. issue as diesels require a certain temperature to achieve top efficiency. The comparison between your monster diesel and the 3b may just be discrepancy in the type of use (more hiway , longer trips, etc.) Bear in mind as "wimpy" as the 3b is, it's still moving around 5000 lbs of vehicle,... ya slowly for sure but she'll get you there. Merry Christmas, Tony
 

MrMoMo

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Driving route has not changed, it's about 35km at a time, 80% of that at speeds greater than 80km/hr

I don't have an EGT gauge, I wish I did.... It'd go well with the turbo I'd like to put in at the same time.
Engine temp gauge is in the normal operating range (same as before)

No harder to start than normal, no smoke (except at startup - and even then it's not a lot)
 
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Driving route has not changed, it's about 35km at a time, 80% of that at speeds greater than 80km/hr

I don't have an EGT gauge, I wish I did.... It'd go well with the turbo I'd like to put in at the same time.
Engine temp gauge is in the normal operating range (same as before)

No harder to start than normal, no smoke (except at startup - and even then it's not a lot)

Given what you have descibed, I would just chalk it up to winter diesel. Dump in some Standyne - about a 1/4 of a bottle with you next fill. Get the performance forumla. It has the cetane boost and the lubricant added to it. They run about $10 a bottle in BC. I notice that with it my rpm is a little higher than nomal. Without it, it is a fair bit under normal: 100-150 rpm below standard summer idle. I have also found a noticeable variation in the diesel. Mohawk/Husky and Superstore/Loblaws diesel seems to be the best compared to Shell, Esso, Petro Canada or Chevron. I think it was MJohn who said that Co-op has the best quality diesel. So try a couple sources.

Also, remember that winter snow tires and driving on snow and ice uses up more fuel on any vehicle compared to summer driving on dry pavement.

Looking at your current economy, I don't think it is that bad given the conditions you are probably driving in.
 
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My $0.02: you might be driving the 3B like it's an F350...

Every time I see an F250/350, the thing is pedal to the metal. For whatever reason, a lot of guys seem to think those Goliaths are diesel dragsters or something.

With the 3B and 2H, less is more, much more, when it comes to fuel pedal depression.

There's a simple equation for Toyota diesel fuel economy, it goes like this: [speed]-1=[mileage]+1.

It works every time...
 
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I agree with the above statement, you can feel the power in the pedel, don't use more then you need... Many times I find my foot to the floor and the egt's rising and I'm not going any faster... Since I've started letting the powerband go the way it wants, my fuel economy increased drastically...
 
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I think this is about average for winter driving in cold weather, including warm-ups.
My 3B got about the same in the winter and about 22-25 in the summer.
Don't sweat it, this is pretty much the standard from what I've seen.
 

MrMoMo

That's not rust, it's Canadian patina...
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My $0.02: you might be driving the 3B like it's an F350...

Every time I see an F250/350, the thing is pedal to the metal. For whatever reason, a lot of guys seem to think those Goliaths are diesel dragsters or something.

With the 3B and 2H, less is more, much more, when it comes to fuel pedal depression.

There's a simple equation for Toyota diesel fuel economy, it goes like this: [speed]-1=[mileage]+1.

It works every time...

Nope, but I do drive my F350 like it's a 3B! If I put my foot to the floor in the Ford - it's scary! -partially because I'm scared of blowing the tranny out on a hard shift, and partially because I can feel the money falling out of my wallet. Every once in a while I'll stomp on it - it can be fun.

I pretty much have to put my foot to the floor in the 60, otherwise I wouldn't go anywhere. Once I am up to speed I don't drive with my foot on the floor, but acceleration wise (the little there is) If I'm not on the floor I would never get out of first gear. I'm wondering if there is something wrong with my accelerator linkage...??
 

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