Im very interested in comments form those with real world diesel experience. So here is the question. How much, if any, does driving style effect the long term reliability of a diesel engine? I ask becuase I tend to drive my vehicle very gently. I don't think I do it out of a concern for long term reliability probably just more out of habit. I rarely accelerate hard or wind out the engine. My 6.7 powerstroke has probably never seen above 3200 rpm. It seems a little silly to ask but am I hurting the engine by not running it harder? I am at 15,000 miles right now. I have done 2 oil changes so far. The first was with T6 and the current one is Delvac 15-40. Any comments would be great.
Driving style
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I do not think you need to drive it hard ever to have the engine last 500K miles.
T6 seems to be a great oil at a decent price.
With no salt in NC I would worry about the transmission rather than the engine. Not saying there are problems with the transmission in your truck, just saying your engine will outlast it.
I would go for a spin on or Magnefine inline transmission filter.
T6 seems to be a great oil at a decent price.
With no salt in NC I would worry about the transmission rather than the engine. Not saying there are problems with the transmission in your truck, just saying your engine will outlast it.
I would go for a spin on or Magnefine inline transmission filter.
Diesels seem to better when they are gotten up to operating temperature and then WORKED-grocery getter short trips don't get them hot enough to burn off the excess carbon, causing turbo problems or worse. "Gently" isn't bad by itself, as long as you get it fully warmed up & preferably hauling some weight when you do it.
I think "gentle" driving contributes more to soot/carbon build up which in the long run can cause problems with DPF's (if so equipped) and especially EGR systems/passage ways.
We run our snow blowers in a pond to induce loads prior to putting them away for the summer and it really clears them out. Runway brooms are used to sweep pavement surfaces for the same effect. The reason we do this is the equipment has a lot of low-speed, high-idle time on the engines and rarely gets loaded except during snow events.
I open up our X35d several times per week to keep it "blown out" and my 35d smokes much less than others I've seen on the road under full acceleration which I attribute to less soot/garbage build up in the exhaust. I believe in running them hard....not abusive by any means, but working the engine to near capacity.
We run our snow blowers in a pond to induce loads prior to putting them away for the summer and it really clears them out. Runway brooms are used to sweep pavement surfaces for the same effect. The reason we do this is the equipment has a lot of low-speed, high-idle time on the engines and rarely gets loaded except during snow events.
I open up our X35d several times per week to keep it "blown out" and my 35d smokes much less than others I've seen on the road under full acceleration which I attribute to less soot/garbage build up in the exhaust. I believe in running them hard....not abusive by any means, but working the engine to near capacity.
JHZR2
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General school of thought is to work the engines... But time at temperature is what effects life of components - time at higher temperatures will cause faster degradation.
That is balanced with sooting, combustive efficiency, hot burn, etc. Depending upon individual parameters of each engine design, certain things may be important or not.
That is balanced with sooting, combustive efficiency, hot burn, etc. Depending upon individual parameters of each engine design, certain things may be important or not.
dnewton3
Staff member
Gentle, smooth operation during warm-up is a good practice.
Once up to temp, today's engines are pretty stout. And working a diesel hard is not really "hard" on it. In fact, I believe that most of today's diesel engine issues are because people baby them, and the soot loading creates all kinds of issues with the EGR/DPF.
If you don't work a diesel hard at least 1/2 the time, then you probably really don't have a need to own one in the first place. Get a gasser; they are very capable and have less issues when driven lightly.
I would say using 15w-40 is not going to hurt it, but it probably won't help, either. Use a 10w-30 HDEO and it will aid in fuel economy a small bit.
Once up to temp, today's engines are pretty stout. And working a diesel hard is not really "hard" on it. In fact, I believe that most of today's diesel engine issues are because people baby them, and the soot loading creates all kinds of issues with the EGR/DPF.
If you don't work a diesel hard at least 1/2 the time, then you probably really don't have a need to own one in the first place. Get a gasser; they are very capable and have less issues when driven lightly.
I would say using 15w-40 is not going to hurt it, but it probably won't help, either. Use a 10w-30 HDEO and it will aid in fuel economy a small bit.
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Highway diesel engines are made to tolerate a lot. Expect to consume two transmissions over the life of one engine. Light load and idling aren't the best for the reasons Bullwinkle and others mention, but you can do it a lot. That said, there isn't much you can change responsibly. If you're driving up a long mountain up-grade, run at the speed limit if safe. Don't be afraid to haul a heavy load when you need to. Just running fast starting out from a red light isn't a good plan. From your description, you just bought more engine than you need.
Industrial engines are sized for an expected load of 75% to 90% of rated max. You know the load and buy the engine accordingly. An industrial or marine diesel should be run at light load as seldom as possible, and idled as short a time as possible when starting and shutting down. If a big ship is ahead of schedule, preferred practice is to shut down and drift rather than run at reduced speed. I had a plant with three 2 megawatt diesel generators (Cat/MaK straight eight 32 cm bore), and the automated start & stop system would bring another generator into operation when the running one reached 90% of max load.
Industrial engines are sized for an expected load of 75% to 90% of rated max. You know the load and buy the engine accordingly. An industrial or marine diesel should be run at light load as seldom as possible, and idled as short a time as possible when starting and shutting down. If a big ship is ahead of schedule, preferred practice is to shut down and drift rather than run at reduced speed. I had a plant with three 2 megawatt diesel generators (Cat/MaK straight eight 32 cm bore), and the automated start & stop system would bring another generator into operation when the running one reached 90% of max load.
The answer is YES, you are hurting the engine! Aren't you at least curious what your truck can do? Go out to a back road and FLOOR IT! Think of it as regular maintenance. There is a reason the pedal goes all the way to the floor.
Originally Posted By: dnewton3
If you don't work a diesel hard at least 1/2 the time, then you probably really don't have a need to own one in the first place. Get a gasser; they are very capable and have less issues when driven lightly.
This school of thought really, really annoys me. Why do people think you have to be hauling tons of freight just to drive a diesel truck? That's like saying you don't need a Corvette if you don't live next to a race track. People buy diesel trucks because they perform much better, they last longer, and they get better gas mileage. They also haul a lot if you need it. Lots of people don't.
Nobody "needs" more than a V6 gas engine in a pickup truck.
Originally Posted By: dnewton3
If you don't work a diesel hard at least 1/2 the time, then you probably really don't have a need to own one in the first place. Get a gasser; they are very capable and have less issues when driven lightly.
This school of thought really, really annoys me. Why do people think you have to be hauling tons of freight just to drive a diesel truck? That's like saying you don't need a Corvette if you don't live next to a race track. People buy diesel trucks because they perform much better, they last longer, and they get better gas mileage. They also haul a lot if you need it. Lots of people don't.
Nobody "needs" more than a V6 gas engine in a pickup truck.
IMO it is all about the load, rpm is carefully limited in todays engines.
If it doesn't get a good workout once in a while you will be prey to a host of issues. Running one hard has never hurt it if everything is up to snuff...
If it doesn't get a good workout once in a while you will be prey to a host of issues. Running one hard has never hurt it if everything is up to snuff...
Babying it and or idling a lot with load the DPF and EGR with soot. We have 2010 Pete that will load the dang DPF if the drivers baby it too much. We've had it out at least twice in its 319k miles to clean it. Same with the EGR. Then again that might be a Cummins thing. My ISX doesn't do it though.
Hi,
matt711 - I have some real world experience with heavy high speed diesel (HHSD) engines - not only in my own vehicles but in many Fleets, various OEMs and in various Countries
In my own case engines were selected via route simulation and experience - and Senieor Driver preferences!
My engines were selected to operate at maximum power and torque most of the time and these were achieved at 1500rpm.This is also the point of best combustion efficiency. Maximum torque commenced at 1200rpm and was constant out to 1500rpm. Max power was at 1500rpm. At 1600rpm the truck was very efficient too and as speed dropped their was the feeling of more "energy" of course. This meant that as power fell off its peak, torque remained constant down to 1200rpm. This gave a lot of Driver satisfaction, was beneficial to economy by reducing the number of downshifts (18spd used as 9spd) and maintained trip times better. On one Route time spent in top gear was around 70%
My engines never suffered carbon build up nor unusual wear. Over many millions of kms my OCIs were averaged at 90k kms. Oil was changed out when soot or Fe levels (seldom others) reached my condemnation point. Tear down inspections showed very little if any wear up to 1m kms
In my experience heavy high speed diesel engines perform best in an overall sense (durability etc) when they spend a lot of their life at or near their most efficient work point!
Most HHSD engines I've been connected with over the last 50 years in various applications "told" the same story....... Those that were incorrectly specced or wrongly applied produced the most operational and technical problems during their lifetime
matt711 - I have some real world experience with heavy high speed diesel (HHSD) engines - not only in my own vehicles but in many Fleets, various OEMs and in various Countries
In my own case engines were selected via route simulation and experience - and Senieor Driver preferences!
My engines were selected to operate at maximum power and torque most of the time and these were achieved at 1500rpm.This is also the point of best combustion efficiency. Maximum torque commenced at 1200rpm and was constant out to 1500rpm. Max power was at 1500rpm. At 1600rpm the truck was very efficient too and as speed dropped their was the feeling of more "energy" of course. This meant that as power fell off its peak, torque remained constant down to 1200rpm. This gave a lot of Driver satisfaction, was beneficial to economy by reducing the number of downshifts (18spd used as 9spd) and maintained trip times better. On one Route time spent in top gear was around 70%
My engines never suffered carbon build up nor unusual wear. Over many millions of kms my OCIs were averaged at 90k kms. Oil was changed out when soot or Fe levels (seldom others) reached my condemnation point. Tear down inspections showed very little if any wear up to 1m kms
In my experience heavy high speed diesel engines perform best in an overall sense (durability etc) when they spend a lot of their life at or near their most efficient work point!
Most HHSD engines I've been connected with over the last 50 years in various applications "told" the same story....... Those that were incorrectly specced or wrongly applied produced the most operational and technical problems during their lifetime
JHZR2
Staff member
Originally Posted By: dnewton3
If you don't work a diesel hard at least 1/2 the time, then you probably really don't have a need to own one in the first place. Get a gasser; they are very capable and have less issues when driven lightly.
I would say using 15w-40 is not going to hurt it, but it probably won't help, either. Use a 10w-30 HDEO and it will aid in fuel economy a small bit.
I would agree but we have a history of long service and reliability with very lightly driven NA and mainly turbodiesels. No soot issues, no EGR issues, only the latest one has DPF, so time will tell, but fine at 70k.
If you don't work a diesel hard at least 1/2 the time, then you probably really don't have a need to own one in the first place. Get a gasser; they are very capable and have less issues when driven lightly.
I would say using 15w-40 is not going to hurt it, but it probably won't help, either. Use a 10w-30 HDEO and it will aid in fuel economy a small bit.
I would agree but we have a history of long service and reliability with very lightly driven NA and mainly turbodiesels. No soot issues, no EGR issues, only the latest one has DPF, so time will tell, but fine at 70k.
When I look back at more or less stock light truck diesel engines, those that do the most short hopping seem to be the most trouble. Those that are driven the most at full operating temp the least and working them at a high percentage of load doesn't really seem to detract from reliability (up to a point).
I've seen a few examples on either side of the coin lately. Here are two '08 Fords F350s with 6.4L diesels. One guy used his '08 as more or less an in-town commute rig. Very occasional hauling or towing. He followed the OE maintenance schedules and used a name brand oil. At 100K the engine failed due to excessive sludge. Another guy uses his truck to haul cars in a three state area, follows the OE maintenance schedule and his 6.4 is A-OK at 165K miles with no signs of sludging. Anecdotal but indicative.
I've seen a few examples on either side of the coin lately. Here are two '08 Fords F350s with 6.4L diesels. One guy used his '08 as more or less an in-town commute rig. Very occasional hauling or towing. He followed the OE maintenance schedules and used a name brand oil. At 100K the engine failed due to excessive sludge. Another guy uses his truck to haul cars in a three state area, follows the OE maintenance schedule and his 6.4 is A-OK at 165K miles with no signs of sludging. Anecdotal but indicative.
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1997 Ford f250HD. 7.3powerstroke 4oed 3.73limited slip
198K. original emission controls.
Bought in 2007 w/ 100k
7,500-10,000 oci's with 15w40/10w30 , fl-1995
Moderate to severe idle times
most shifts are below 2100-2200rpm, so lower speeds.
tows less then 30% of miles.
no problems so for.
ken
198K. original emission controls.
Bought in 2007 w/ 100k
7,500-10,000 oci's with 15w40/10w30 , fl-1995
Moderate to severe idle times
most shifts are below 2100-2200rpm, so lower speeds.
tows less then 30% of miles.
no problems so for.
ken
I do tow during the Summer months but the load isnt that great, maybe 5-6000 pounds. I went with this truck becasue my F150 was gutless when towing my boat and I could do no better than 10 mpg.
So yes, the F250 is probably more truck than I need 70% of the time. But I really like it when I tow the other 30%.
Ford calls for 8-10K OCIs with my driving style. I have 15,000 miles and am on OC number 3. With the drain valve it's such a simple task to change the oil that I don't see much point in stretching things out. Hopefully the more frequent changes will prevent sludge.
So yes, the F250 is probably more truck than I need 70% of the time. But I really like it when I tow the other 30%.
Ford calls for 8-10K OCIs with my driving style. I have 15,000 miles and am on OC number 3. With the drain valve it's such a simple task to change the oil that I don't see much point in stretching things out. Hopefully the more frequent changes will prevent sludge.
When I started driving trucks in the '70's they were all old British trucks from the '60's...Doug Hillary will know the sort. Most struggled with no load, and they were driven WOT to the govenor for every shift, when power dropped off they were downshifted and run up to the govenor again. I drove an old Ford D series a few weeks ago - it was 70kph WOT on the govenor top speed, 2,200rpm redline. They were worked hard, but probably not very high stressed.
These days engines rev much higher, and the tachos have a green zone - one light Japanese truck I drove today had a redline of 3,500rpm, but a green zone from 1,000 to 2,500rpm. You can screw them out to the redline, but they don't hit a govenor and really work much better in the green.
These days engines rev much higher, and the tachos have a green zone - one light Japanese truck I drove today had a redline of 3,500rpm, but a green zone from 1,000 to 2,500rpm. You can screw them out to the redline, but they don't hit a govenor and really work much better in the green.
My om617 has 270,000mi on it. I run up to 4500rpm on full throttle. i notice after long highway trips of 3000-4000 rpm constant (because its geared low), it runs alot better the next few days. it starts faster and has better acceleration. i also get better mpg at higher speeds and rpm vs lugging it.
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