[Bearcat]

looking to see whats everyone is getting these days. Please list type of engine and your miles per gallon. Also checking to see if mine is comparable to anyone else.
I have a cat 3126B 8.2 liter and get around 8.6 mpg.
I think this is low so trying to compare. Will also give me an idea on my next engine to look for in my next truck.
Happy New Year and safe trucking.
Randy

[Dreamer]

On my last long trip, Columbus Ohio, to New Orleans Louisiana, I managed 12.77 mpg, with a 225 Cummins in a 1996 FL70. Mind you, this was straight interstate driving the whole way. I normally averaged about 10 mpg on most trips if I kept it below 65 mph.

[Olko]

Randy

We have the same engine, with a 6 speed behind it. We have figured our mileage on individual trips at different speeds, and came up with the following averages; at 55 mph, we averaged about 10.5 mpg, at 70/75 mph, we averaged about 7.8 mpg with a tailwind. Our overall average is 8.5/8.6 mpg, including idle time. This figure is probably lower at this time of the year, because of the cold and slow freight increasing the idle time. Hope this helps.

[Weave]

You are getting about the right avereage MPG for the CAT 3126 in its 250 HP form. This engine is getting a very bad reputation for being extremely expensive after 400k miles. A rebuilt CAT costs about twice as much as en equal size Cummins. A rebuilt 3126 installed is between $10-13k. Its 7.2 liters, not 8.2 as you mentioned. Older Cummins C8.3's @ 225 HP average about 9 MPG, B5.9's @ 230 HP about 11. The computerized Cummins engines (ISB,ISC) I hear get excellent mileage- about 11 MPG on the ISC 8.3 running 315 HP! Wow! I'd like to know if this is true or not if someone out there is running one. I'm in the process of planning my next straight truck, which will be a stretched class 8 tractor using both rear axles, probably with DDC series 60 power. Still hoping to average 10 MPG with this setup. Maybe a BIT hopeful!
--Weave--

[allen]

I have 38k on a Series 50 Detriot/w Eaton 9 spd and my average for the 38k loaded and empty so far is 10.1, I don't see a lot of difference in my mileage loaded or empty. I try to do low rpm shifts but i run pretty hard on the interstate system 65 to 75 depending on what the speed limit is, also I try not to idle any more than I have to which is why I am looking into a generator.

[RichM]

I have a Cummins C 225 with a Fuller 6 speed and generally get between 11-12.5 MPG,Thats running at 65 mph or less. Sometimes running out west with strong east winds might drop down to 10,I have 460,000 miles on the engine and have never gotten less then 10. It is a excellent durable,cheap to rebuild engine.One time I asked the Cummins Service Manager,"How does Cummins get extra power out of this block?" He said "All they do is use larger injectors and crank up the turbo and fuel pump pressure". So your 225 HP engine is stressed and built for 300 HP..With good maintenace should easily last 500,000 miles b4 a overhaul..

[vernon946]

We have the 3126B at 210 hp. We average almost 9mpg, but only because we run at 63mph. We can do 70 but then begin looking at 8mpg. We also have a generator on the truck.

Vernon in C2197

[NEVERHOME247]

I HAVE A 2000 FL132 CLASSIC XL, CLASS 8 TRACTOR I CONVERTED INTO A EXPEDITER. TANDEM AXLE, SERIES 60 DETROIT 500HP, 10 SPD ROCKWELL TRANS. I AM GETTING ABOUT 8.75 MPG AT 65MPH AND SOMTIMES I GET UPWARDS TO 10MPG. I HAD A 99 FL70 WITH 250 CAT PRIOR TO THIS AND I GET BETTER MILEAGE WITH THE BIG DETROIT. I KNOW IT SOUNDS HARD TO BELIEVE BUT ITS TRUE. BUT I AM ONLY TURNING ABOUT 1200 RPM AT 56 MPH AS OPPOSED TO THE 2100 RPM I WAS TURNING AT 65 MPH WITH THAT LITTLE CAT. ANOTHER GOOD THING IS IT DOESN'T BLINK A EYE AT A HILL, UNLIKE THE FL70 I HAD THAT COULDN'T EVEN PULL A STEEP GRADE EMPTY. THE RIDE IS SO MUCH BETTER AND ITS FAR LESS NOISE IN THE INSIDE OF THE CAB. WOULD NEVER GO BACK TO A BUSINESS CLASS TRUCK AGAIN.....

[simon says]

I have a Pete 330 with a 3126B 275hsp/860T, 9 spd. Fuller, 4.11 R.A.(ouch)and my overall length is 37.5 ft. I average 8.6 mpg at speeds of 62-63 mph. Driving at that speed I can do as well as 9.3 staight hywy., unless grades are consistently steep. I probably burn off a gal/hr idling overnight @ 1000rpm. I suspect at 3.9 R.A. would increase the mpg figure by .5 mpg, but for this engine, lower that that (3.7) you cannot climb hills. I will tell you that my configuration can climb hills with the best of them, and I can play tag with big trucks who try to travel 65 or better. One last note for those interested; Speedco offers 10W30 & 10W40 SB ( synthetic blend diesel oils) with fuel saver spec.and my current winter mpg figures reflect that. I can extend drain intervals to at least 10K (I have shallow sump)and fuel econ. has increased by .5- 1 mpg, and I get better start-up without assists.

[Bearcat]

To my knowledge, you shouldn't have to change oil at 10000 unless
your oil sample dictates. I have the 3126B cat in my fl70 (deep sump) and am researching putting synthetic delvac in it. I am not sure about the smaller diesel engines but the bigger ones can go 50000 without a oil change on synthetic. You have to do the oil samples during regular entervals to make sure everything is ok, but check before you do it.
Good luck
Randy

[simon says]

I understand your point viz. drain intervals, however, MI. Cat advises 10K drain intervals based on the fact that this engine with the H.E.U.I. fuel delivery system relies so heavily on clean oil. The deep sump system drain interval is 10K by the book (mine is only 6K)- so for me, 10K is a plus. I do think I could go to 12K. We'll see.

[geo]

i have a 2001 weststar with c10 cat getting 9.64 gals per mile
with a 335 hp with easton slect 10 speed, it's class 8 as
a c unit, also have proheat ice gen set and this saves a lot on the engine have 49 hours of idle time on engine, sept 22,2000
per cat 250 hours on the engine equals 10,000 mile.
so idle and running adds more fuel down the the
drain, add a genset to your unit and save about $400 to 600
per months on fuel, to look at proheat ice go to georgebmcdonald.com also pick up copy of truck stop guide to

We're probably comparing apples to oranges here, but we have a 2001 International 4700 with a 230 hp DT466E and an Allison MD3060 trans w/4.10 rears and are getting 9.36 mpg. We seldom run under 60 mph and often faster (70 minimum going to KC) with a fair amont of idle time.

Been looking at one of the "Nose Cones" for the box. Has anyone had any experience with it as to the alleged mileage improvements? The manufacturer claims at least .5 mpg improvement.

[Road_dog]

Ive got the same engine(3126)380thou,miles but with the 7 speed, according to DDL software my average on the east coast is 8.5 to 8.8.
Did a trip out to Iowa recently and did 9.1...could hav been better, but my right foot said get there soon.Avg speed was 68mph.

As for the talk on sinthetics,,,,I know a driver who just replaced his 3126 cat,(180 000 MILES)BOOOM...he had changed to sinthetics 100 thou pryer...Id be careful....I'm not sold on this sinthetic thing yet.
The talk about the class 8 stretch is the way to go.,,,This is my last FL80,

[bojangles1]

I have a 2000 FL106 with a series 50 Detroit in it. I average about 9.6mpg running 65mph and over. Running 55-60mph I get about 10.5-11mpg. The engine has 250,000 miles on it with a 9 speed transmission.