Mercedes benz 450 hp problems
 

what kind of milage are you getting with your renegades or others with this engine.\?my is a 32 ft tandem & 40 ft stacker 55000 lbs gross 4.5 mpg. i havr a issue with the fan coming on at 75 mph on warm days for about 20 seconds at about 210 degrees temp drops to 190 within 15 seconds. two dealers have give up & said this is normal,it did not do thid when new. i have replaqced the thermosats twice one water pump & one radiator for nothing. thanks for any info mark young 919 427 2747

Re: Mercedes benz 450 hp problems
 

Mark, I have a showhauler with this engine in it. I have a 30' box with a 34' stacker. Towing, I get between 6 and 6.5 mpg. If I travel, use the genorator and then fill up it ends up being in the a lot less due to the genorator consumption. As far as the fan, mine does the same thing if its hot outside. I've never been concerned with that. I've owned mine since 2005 so I don't think you have an issue with the fan.
Chuck

Re: Mercedes benz 450 hp problems
 

Thanks for the info. The fan is annoying though. What do you think of the mpg difference? My truck 12 speed autoshift & 3.58 gears 11.22.5 tires

Re: Mercedes benz 450 hp problems
 

My Haulmark does it too (I have a Cummins) and it drives me nuts sometimes. They have looked and looked and still cannot find any problems and said "It must be normal but it does not seem right". As far as milage when I first got mine I thought it was going to kill me in fuel and regretted my decision. Now that I have just 14K miles on it the fuel mileage has almost doubled. I hoping with 4 dollar diesel by the time it gets to 30K it doubles again LOL.

Re: Mercedes benz 450 hp problems
 

Same set up as mine, I would guess its because of the tandum and the larger trailer. Haven't weighed it in years, but I don't remember it being at that weight.
Chuck

Re: Mercedes benz 450 hp problems
 

Thanks guys for the advice. Anybody else have any ideas on my fuel milage 4.5 mpg or the fan . Please help thanks mark young

Re: Mercedes benz 450 hp problems
 

it would seem my 358 rears gears are causing both the fan problems and poor fuel mileage. a freids truck has 3.21 ratio. what do you other 450 mercendes owners have for gear ratios? i drive at 80 and max speed is 83 engine is maxed out a lot of times on open interstates/ my truck has mercendes axles that donot offer anything between 2.40 and 3.58 thanks for any imput.

Re: Mercedes benz 450 hp problems
 

I would back off of the throttle and run at a slower speed. I have a M2 with a 330 hp Mercedes. I run 65 and get about 8.5 mpg hauling 15000 LB trailer. I make just as good of time in the toter running slower than in the dually because I don't have to stop for fuel, food or bathroom. I don't think it's a good idea to run maxed out. That probably why the fan keeps coming on. Mine never comes on at highway speed even in hot Florida weather. You are pushing a lot of wind at that high speed.

Re: Mercedes benz 450 hp problems
 

Thanks mike but i mite git rearended at that speed!!!! What gear ratio does yours have? Thanks again

Re: Mercedes benz 450 hp problems
 

I've got the answer, Try driving past a state trooper @ 80mph towing your trailer!!!!

Re: Mercedes benz 450 hp problems
 

Showhauler with stacker at 65 to 70 I get 8.5 to 9. Had one time I had fan running all the time on hot day. I was told the use of the incab AC was causing the temp to rise so fast.
I did replace a sensor and when I opened the line air bubble came out and has been fine since. May have been giving a false temp signal? False pressure?

Re: Mercedes benz 450 hp problems
 

Look at the turbulance you create with your rig. I have a wing on both my motor homes. Worth 20% fuel economy and abut 10 degrees operating temp. Notice when you go through the rain how much turbulance you create, or on a road with a dusty side, see how much dust you create on the curb side. You should try to get the wind off the front of the trailer and over the trailer smoothly. Just look at the big trucks on the highway. Notice how much effort is made to make it go through the air smoothly.