1,180 Mile Tank

[Diesel_Dave]

My max sidewall is 80 psi. If I remember correctly the recommended pressures are 55 psi for the front, 45 psi for the rears. If I ever carry a heavy load, I'd probably decrease my pressures a little, but most of the time I run unloaded or only lightly loaded. It's been about 3 months (3,500 mi) since I bumped up my pressures from 60 to 70. So far I haven't noticed any unusual tread wear. I probably should take another close look to make sure.

80 psi max sidewall seemed like a lot to me when I first looked at it as well, but I guess I just have "stronger" tires. My wife has 17-inch tires on her Blazer and her max sidewall is only 35 psi. I guess it just depends on the tire.

[Diesel_Dave]

Originally Posted by Rick323

Are you putting the heaters on the oil pan? or are you going to put them on the transmission or differential? I'm pretty sure the block heater on my ford is 1150 watts-that's good enough for the engine (oil, antifreeze...everything). I plan on putting a couple of heaters on my car and trucks, the trannys are definitely getting one.

Right now I have two heaters. I plan on putting both of those on the oil pan. Later, I may put one on the tranny and another one on the differential.

I'm a little confused about what you said about your block heater being good enough for everything. If it's a coolant heater it heats the coolant. If it's an oil heater it heats the oil, etc. A coolant heater won't heat the oil no matter how big it is. Granted, if your coolant heater heats up the coolant and block, your oil will heat up faster once you start the engine, but it hasn't heated the oil or tranny at all (directly).

[jakobnev]

Maybe you can get your consumption in metric to less than your displacement!

[Diesel_Dave]

Originally Posted by jakobnev

Maybe you can get your consumption in metric to less than your displacement!

That would be cool! I think that works out to be just over 35 mpg. That's pushing it. My goal at this point is to get a 90-day average of 36 mpg someday. I still have a way to go, though (another 14%)

[slowmover]

I plan on hooking up both the oil pan heaters and the coolant heater to the same timered power strip--that way I only have one thing to plug in.

There are some discussions about oil sump heaters on BITOG and the recommendation is to make sure the oil temp (in-sump) does not exceed 150F as one will start to cook the oil. (Yes, I realize that 260-270F is often cited for oil temp max on a running engine. The concern here is that the heaters create hot spots without pump circulation; bad chemistry starts to form IIRC). The happy curve is short. An email to Cummins wouldn't hurt to help clarify this.

I'd be inclined to use them on the trans and differential as you've noted, but with electrical outlets (perhaps [2] separate 20A type) and cabling built to withstand the amperage draw. GFCI's are not happy with this sort of set-up I'm told.

It would be worth some planning as well to determine actual in-sump temperatures, not just IR gun readings of the pans/cases exterior.

So far I haven't noticed any unusual tread wear. I probably should take another close look to make sure.

A tread depth gauge is about $5 at NAPA. I trend the treadwear at 20k mile intervals (of which there are from 5-7 on the OEM Michelin tires when driven for long life).

80 psi max sidewall seemed like a lot to me when I first looked at it as well, but I guess I just have "stronger" tires. My wife has 17-inch tires on her Blazer and her max sidewall is only 35 psi. I guess it just depends on the tire.

The 3/4 & 1T trucks use a Load Range E tire capable of supporting in excess of 3,000-lbs each at full pressure. Matching load to pressure brings best results (plus maybe an increase of 10-15% to help stiffen the sidewalls, IMO). My truck -- identical in most respects -- calls for the LR-E tires to be run at 50FF/50RR when solo, and 50FF/70RR when fully loaded. My repeated highs of 27 mpg were achieved at the 50/50 pressures. I have moved to 60FF and 50RR to help with any potential "scrub" in turns on the front. (My first set went 120k with 4/32's remaining; this first replacement set may make take the truck to 250k).

The wifes Blazer is using a P designation tire for soft ride. If you ever want to set it up for better highway/towing stability, then an LT [Light Truck] tire -- as recommended by Michelin or other -- would be best. This might also help with FE somewhat.

Thanks for the update. Sooner rather than later I hope to make a start on some mods for my truck.

.

[pletby]

Diesel_Dave you rock man! I'm still trying to get my CAR up to that fuel efficiency. Wow! I'm actually taking this pretty seriously too. Time for those mods I've put off.

[Diesel_Dave]

Originally Posted by slowmover

I plan on hooking up both the oil pan heaters and the coolant heater to the same timered power strip--that way I only have one thing to plug in.

There are some discussions about oil sump heaters on BITOG and the recommendation is to make sure the oil temp (in-sump) does not exceed 150F as one will start to cook the oil. (Yes, I realize that 260-270F is often cited for oil temp max on a running engine. The concern here is that the heaters create hot spots without pump circulation; bad chemistry starts to form IIRC). The happy curve is short. An email to Cummins wouldn't hurt to help clarify this.

I'd be inclined to use them on the trans and differential as you've noted, but with electrical outlets (perhaps [2] separate 20A type) and cabling built to withstand the amperage draw. GFCI's are not happy with this sort of set-up I'm told.

It would be worth some planning as well to determine actual in-sump temperatures, not just IR gun readings of the pans/cases exterior.

So far I haven't noticed any unusual tread wear. I probably should take another close look to make sure.

A tread depth gauge is about $5 at NAPA. I trend the treadwear at 20k mile intervals (of which there are from 5-7 on the OEM Michelin tires when driven for long life).

80 psi max sidewall seemed like a lot to me when I first looked at it as well, but I guess I just have "stronger" tires. My wife has 17-inch tires on her Blazer and her max sidewall is only 35 psi. I guess it just depends on the tire.

The 3/4 & 1T trucks use a Load Range E tire capable of supporting in excess of 3,000-lbs each at full pressure. Matching load to pressure brings best results (plus maybe an increase of 10-15% to help stiffen the sidewalls, IMO). My truck -- identical in most respects -- calls for the LR-E tires to be run at 50FF/50RR when solo, and 50FF/70RR when fully loaded. My repeated highs of 27 mpg were achieved at the 50/50 pressures. I have moved to 60FF and 50RR to help with any potential "scrub" in turns on the front. (My first set went 120k with 4/32's remaining; this first replacement set may make take the truck to 250k).

The wifes Blazer is using a P designation tire for soft ride. If you ever want to set it up for better highway/towing stability, then an LT [Light Truck] tire -- as recommended by Michelin or other -- would be best. This might also help with FE somewhat.

Thanks for the update. Sooner rather than later I hope to make a start on some mods for my truck.

.

With regard to the oil temps you're right--I wan't to be careful not to cook it. I'll do some digging to see what I can find as far as specs on the max temperature. In theory a pad on the sump should provide at least some "mixing" due to convection (the heater is at the bottom so the hot oil rises, the cool oil falls). Concern about overheating is another reason I went with the 2 separate pads. I want to be able to have all the heaters on an equal amount of time. If 2 heaters prove to be too much then I'll just use the one.

Just a thought...has anybody heard of a temperature probe that you could slide down the dipstick tube (not to replace the dipstick permanently--just to check the actual internal oil temp). I guess I could just get a thermocouple with a long lead. Hmmm...I'll have to look into that.

As far as the amperage draw I think I should be okay. I'm pretty sure the block heater is 750 W. Even if I add all 4 150 W pad heaters that brings the total to 1350 W wich equates to 11.3 amps. That shouldn't be any problem for the outlet, but I'll have to check the amperage rating of my timered power strip.

As far as the tread wear, I looked at it pretty closely (visually). I think I'll have to get a tread gauge to really know--my eyes aren't precise enough.

[Rick323]

Originally Posted by Diesel_Dave

I'm a little confused about what you said about your block heater being good enough for everything. If it's a coolant heater it heats the coolant. If it's an oil heater it heats the oil, etc. A coolant heater won't heat the oil no matter how big it is. Granted, if your coolant heater heats up the coolant and block, your oil will heat up faster once you start the engine, but it hasn't heated the oil or tranny at all (directly).

When I said everything, I meant in the engine. Like you said the coolant heater transfers heat through out the engine. It heats the oil (to a point) by conduction-just by having everything else around it warmer.

My initial oil pressure with the block heater on in cold weather is lower than it is with out it on. That has been the case for all of my vehicles with block heaters (93 dodge, 99 f 250, 05 Tacoma). On my tractors you could actually feel the difference by comparing the pan to other parts of the tractor.

[Tygen1]

I have 150w adhesive pad heaters on both my oil and trans pans. The max temp they can achieve is around 100 degrees on my 5 quarts of oil 4 cylinder motor. I don't think you will have to worry about overheating the oil unless you go a bit overboard on your heater. Mine are 150w because that is the size of pad that fits the flat part on the bottom of my pan. I'd think that if you just get an appropriate sized pad, then you will probably see a similar result as I have.

[Diesel_Dave]

Tygen, how did you measure your temperatures (100 F)?