3126 upgrade

[rick Kirchner]

Well I searched and didn't find a lot, so here's a question for Dave Atherton:

I have  300 hp 3126.  The last time I had it at a CAT dealer they ran the serial number and told me it could be upgraded to 330 HP.  Now I'm not all that thrilled about 10% more hp - but surprisingly, the torque curve for that engine mapping is really flat compared the the 300.  So it seems from a drivability standpoint, it's a good idea.

What are the downsides?

Also, I've received a wide variety of prices when I've inquired of various dealers.  Best price was $650, which for just plugging in a programmer and doing its thing, seems steep, but not compared to some of the other quotes I got.

I could see where at the purchase of the coach, there are warranty issues to consider, but after a significant period of time, should just be a labor charge for the most part. 

[Dave Atherton]

Rick, yes you can upgrade 25 horse power using Cat ET diagnostic service tool with An 3126 A model
engine. My suggestion along with increased horse power comes more heat,  increase fuel, more wear and tear on engine. Your engine at build time than tested in 3 different spec frames, than set up
for best performance and horse power. At this point arrangement number is assigned to your engine
serial number( which in your case 300 h.p. ) The price you put out $ 650.00 is misleading and have several motorhomes lay claim to how much h.p.engine is putting out only to find out the engine
had not been turned up. Which was verified doing engine Diagnostic ECM readout engine h.p. Again
Just my suggestion but the negative results will out weight the positives results. Your 3126 A
model fuel mileage Present at 55 miles per hour 10 mpg. Run up the engine mileage drops 7-8 mpg.
Dave Atherton Retired Cat Mechanic

[Mike Shumack]

Not to hijack this thread - but related...

Can I derate my 525 C-13 with programming (say to 500HP) to get an improvement in fuel economy? I get about 5.5 mpg now. I'd like to get 6.5 to 7 mpg.
Or would just "easing off the throttle pedal" and keeping my top speed to 65 mph give me the same results?

[Dave Atherton]

Mike, I dont want you to think I sound negative when answering your question. First a person can
do just about anything with engine so to speak and all comes at a price. My suggestion leave it
alone and wear lighter shoes while driving. ( slowing down fuel mileage increase a plus, need extra
power over mts, a plus.) The nice part, your engine built and tested at present to do just that.
Dave Atherton Retired Cat Mechanic

[Mike Shumack]

My suggestion leave it alone and wear lighter shoes while driving.

Good advise as always. 
Asking questions is cheap - actually doing something and/or spending money, is usually where I draw the line.

[Lee Welbanks]

Mike, With my 06 PT I'm getting 6+ now and I usually cruise around 60 to 65 mph, seems like the more miles I put on it the better the mileage gets.

[rick Kirchner]

thanks dave