Tip Steps To Increase My Diesel MPG

[Rich W.]

When I had my 4369 Ventana I never tired the Economy mode. I guess my thinking was that my coach was always loaded plus I was always pulling a trailer with a vehicle and motorcycle. Of course I averaged 6.5mpg for the three years we had it also.

As far as the cost of additives. I believe Cummins (and I know Ford) suggests additives in the fuel for lubrication purposes. Also, most diesel additives give you additional cetane. Most of the bio-diesel we end up buying is 40-42 cetane. Our newer diesel engines like to get their best fuel economy on cetane ranges from 45-55.

For years (4 different diesel engines) I just used Diesel Kleen as my additive. It possibly increased my mpg slightly but I always figured it was lubricating my injectors. When you figure this XDP additive only required an ounce per 32 gallons it comes out about 1/5 the price of Diesel Kleen. So far I'm finding it is about 100 times better than Diesel Kleen for my application, so well worth the few pennies per gallon it is costing me.

Good info - I’ll look into additives. Thanks!

 

[Trucker Bob]

I have been using These Amsoil products in my 96 Dodge Cummins and my VW Passat you might want to check them out. The only problem is I get them shipped so a problem if you full time.
TB

https://www.amsoil.com/c/diesel-additives/18/?zo=5014722

 

[redbaron]

Be very cautious with K&N on diesel engines. It allows too much airflow, and can introduce dust that will pit the cylinders.

 

[bpaikman]

I changed my air filter before this trip (it had about 25k on it and was two years old) and Ive been using the economy “mode” shift strategy almost exclusively on this trip and will continue to do so except where it just isn’t tolerable.

Also traveling at 60 mph, much to the consternation of other travelers out there, although I do my best not to hold things up. My goal is to break into the 9 mpg range. We’ll see in a couple days. Crossing the Sierras didn’t help much but I have a lot of low elevation, more or less flat travels ahead.

I’m not sure about additives and also wonder about the cost of XDP and others per tank and how that affects the final cost per mile. I’ll do a little research on XDP. I doubt I’d see 1.5 mpg in this rig, but any improvement would help.

Pardon a dumb question but what is economy mode?

 

[Rich W.]

Pardon a dumb question but what is economy mode?

Its just a shift strategy that causes the trans to shift early and keep the engine at lower rpm to save fuel. It only has an effect during acceleration where it up-shifts earlier (too early) and on grades where it down- shifts later (too late). Its accessed by depressing the mode button on the top right of your shift panel. On the open road cruising in 6th, it makes no difference.

My plan was to use it almost exclusively on this trip to see if I could save some fuel, but I’m finding it almost totally useless, as pushing 32,000lbs with an ISB takes all the capability this thing can muster. Its almost not even functional in econo-mode when trying to accelerate or climbing a grade and as soon as you shift for it (which I find necessary) rather than wait for the program to get around to it, you‘ve defeated purpose. I typically shift earlier than the trans would in normal mode when starting up a grade.

 

[gibsito]

He also showed me his re-usable/washable air cleaner he uses. It is a K&N filter. It allows better air flow, still filters the same, and increases mpg another 1 to 1.5 mpg. I have used K&N air filters on my Harley's for several years and they deliver as promised. I just ordered one to fit my F350.

There's an interesting video out there by "Project Farm" where he tests air filters of several types, including the lifetime, washable K&N. The K&N had good airflow but the worst filter rate. The difference was pretty dramatic. I've been running one in my 5.9 12v Cummins for years, and it worried me a little to see that. I haven't changed it out yet, but I am mulling it over. The video is here.

Regarding MPG, I have typically gotten 16 to 18 in my 1st gen Dodge (with truck camper) but recently did some performance upgrades that may have dropped that down to 15 to 16. "Economy Mode" on this old manual truck means less pressure on the right foot. I've been driving it at 60 for years when towing my car, and no more than 65 when not towing. Performance upgrades included fuel pin, slight turn of the max fuel screw and 3,200 rpm governor spring. It made a very nice difference in power, but I want that mpg back again. I advanced the injection pump 1/8" recently and am taking it on a trip to see if that helped any. Leaving in a few hours.

 

[FL-JOE]

Interesting video. K&N did some pretty extensive testing and their results were almost the opposite. They showed their products filtered better than paper OEM filters.

Recently we were on a long motorcycle trip out to Texas. Unknown to me I had pumped some bad gas into the Harley. Got to a dealer and one of the things he checked was my throttle body assembly. He said it was as clean as a brand new bike, and of course at the time my bike had over 30,000 miles on it. So through personal experience, at least on my motorcycles, I am sold on the performance of K&N air filters.

 

[gibsito]

Interesting video. K&N did some pretty extensive testing and their results were almost the opposite. They showed their products filtered better than paper OEM filters.

Recently we were on a long motorcycle trip out to Texas. Unknown to me I had pumped some bad gas into the Harley. Got to a dealer and one of the things he checked was my throttle body assembly. He said it was as clean as a brand new bike, and of course at the time my bike had over 30,000 miles on it. So through personal experience, at least on my motorcycles, I am sold on the performance of K&N air filters.

That's good to know. I know that K&N has been blamed a lot for damaging MAP sensors but their own investigation of it found that many of those sensors weren't damaged at all, and they suspected unscrupulous shops of replacing them unnecessarily and then blaming K&N for the supposed damage. Doesn't sound too far fetched to me. I've been burned by mechanics before so prefer to do as much of my own work as I can.

 

[FL-JOE]

Changed out the OEM filter yesterday morning. The old one was pretty dirty.

Did a round trip to Chicago and back, over 300 miles total. Used eco mode on my 6.7 diesel (non-towing) and stayed around 70 to 72mph. For the whole trip averaged 19.5mpg. I expected closer to 20mpg and maybe even over but I did get stuck in some construction traffic on I-55 and the Tri-state up by the city.

 

[Rich W.]

Well the best Ive done on this trip is 8.9 and 7.9 is more common. Using econo mode, driving 55-60, just towing a jeep, pretty mild terrain. So I’d say you‘re doing good. About 2500 miles since June 11.