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Unread 07-24-2013, 06:15 AM   #46
Newtons3
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Ive been into hundreds of engines run on Rotella and sent thousands of oil samples out. Ive never seen Rotella gum up anything. All things considered, those were some of the cleanest and longest running engines I dealt with. We can and, for that matter, will always argue what oil is slightly better than everything else and what oil is detrimental to our engines. I personally wont run AMSOIL, Castrol, Havoline, or Quaker State and I dont darken the door of Wal-Mart or AutoZone but that has nothing to do with facts about oil. The truth is, about 80 percent of quality oil out there, including dino oil, is overkill for our engines.

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Unread 07-24-2013, 06:15 AM   #47
mschi772
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I think we've got all the "big" stuff covered already, but I wanted to mention that I've always wondered if a rear air deflector might help to alleviate some of the large low pressure zone generated by our brick-shaped butts at speed. Something to experiment with if you'd have the chance.

Aerodynamically, if you don't want to invest in fabbing-up a whole belly pan, there were stock front skid plates that, despite the small amount of added weight, help aerodynamics quite a bit. You'd gain a slight amount of MPG while also gaining some slight front-end protection. It's not perfect, but it's a bolt-on that you could do for a small win-win.

FastPlastic blocks-off a good portion of his/her grill. He/she has never had a cooling problem, but that still makes me nervous given the XJ's cooling system. I think I'm going to try it during the colder months though if I ever have the time to fab-up some plastic panels that I can pop in and out of each grill section as needed.

(Knowing the benefits of ZDP doesn't make you an idiot. Thinking that it is the end-all-be-all for flat-tappet engine lubrication and using ludicrous amounts of it would make you one of the idiots I speak of, though.)
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Unread 07-24-2013, 06:24 AM   #48
Newtons3
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The aerodynamic stuff Ive seen indicates that a deflector screws up more than it helps unless you are trying to get more downforce. The only thing Ive seen work are wings like they run on the back of some van trailers now which teardrop the rear.
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Unread 07-24-2013, 02:03 PM   #49
Charley3
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Quote:
Originally Posted by Newtons3 View Post
Ive been into hundreds of engines run on Rotella and sent thousands of oil samples out. Ive never seen Rotella gum up anything. All things considered, those were some of the cleanest and longest running engines I dealt with. We can and, for that matter, will always argue what oil is slightly better than everything else and what oil is detrimental to our engines. I personally wont run AMSOIL, Castrol, Havoline, or Quaker State and I dont darken the door of Wal-Mart or AutoZone but that has nothing to do with facts about oil. The truth is, about 80 percent of quality oil out there, including dino oil, is overkill for our engines.
I too would not run Amsoil, Castrol, Havoline, Quaker State, or Walmart oil. Your list of don'ts matches mine, except I also wouldn't run Rotella 5/40 because it has extremely high ZDDP, which allegedly can clog cats.

It is interesting that our list of don'ts is almost identical.

Also, let me add that every report that I've see of alleged lubrication failure allegedly related to low ZDDP was Castrol or Havoline.
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Unread 07-24-2013, 02:12 PM   #50
Charley3
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Quote:
Originally Posted by mschi772 View Post
I think we've got all the "big" stuff covered already, but I wanted to mention that I've always wondered if a rear air deflector might help to alleviate some of the large low pressure zone generated by our brick-shaped butts at speed. Something to experiment with if you'd have the chance.

Aerodynamically, if you don't want to invest in fabbing-up a whole belly pan, there were stock front skid plates that, despite the small amount of added weight, help aerodynamics quite a bit. You'd gain a slight amount of MPG while also gaining some slight front-end protection. It's not perfect, but it's a bolt-on that you could do for a small win-win.

FastPlastic blocks-off a good portion of his/her grill. He/she has never had a cooling problem, but that still makes me nervous given the XJ's cooling system. I think I'm going to try it during the colder months though if I ever have the time to fab-up some plastic panels that I can pop in and out of each grill section as needed.

(Knowing the benefits of ZDP doesn't make you an idiot. Thinking that it is the end-all-be-all for flat-tappet engine lubrication and using ludicrous amounts of it would make you one of the idiots I speak of, though.)
I did buy that stock front skidplate. Not installed yet.

I do want to block off part of grill in the colder months. That will help me stay at 210F in Winter.

I don't want to much ZDDP. Enough is good. To much offers no lubrication benefits and can allegedly clog the cat. So I am not in favor of ludicrous amounts of ZDDP. For example, Rotella 5/40 has way to much ZDDP for a gas engine with cats, IMO. I think it might clog the cat eventually. Mobil One 5/40 only has a little more ZDDP than a typical gas engine oil.
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Unread 07-24-2013, 03:15 PM   #51
mschi772
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Since its a bit off-topic, I'll stop after this little comment: regarding too much ZDP, studies have shown that another consequence of too much can actually be increased wear. I forget the science behind how the wear was caused, but he fact remains that too much or too little can both have negative wear consequences.

P.S. No need to respond to this because ill be researching it myself, but food for thought: Isn't ZDP only a concern for a cat if you're burning oil? Though I've never heard of someone fouling a cat with T6 (it is approved for use in gas engines), and a ton of people use it. (Fun fact: it's the phosphorus in ZDP that's specifically the culprit with cats)
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Unread 07-24-2013, 06:01 PM   #52
Charley3
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My full size Buick Park Ave is setup for hypermileage, except for having snow tires on it.

I use Mobil One 0/40 in it. Perhaps not ideal for hypermileage, but I think it protects engine really well. I have it running slightly hotter than stock by using a 205F thermostat.

It uses many of the ideas in this thread. This car is a smashing success at hypermileage for a full size luxury car with a lot of power.

I just did a 1 hr road trip driving 69 to 74 depending on traffic. It averaged 34.8 mpg, even with snow tires on it!

If I had highway tires it'd be even better. Like maybe 38 mpg.

Part of the goodness is it's 90F day here. That helps, along with a few mods i did.

My power is actually a little better than stock. This car has big balls if I step on it, but I avoid stepping on it when hypermiling.

Having an awesome road trip! Just arrived at destination. Will drive back home later today.

Edited in Later: Just got home. It averages 34.5 mpg on the way home. I drove 70 mph, except when idiots cut me off (rush hour). So fuel economy was consistant both directions.
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Unread 07-24-2013, 06:20 PM   #53
Newtons3
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Quote:
Originally Posted by Charley3 View Post
I too would not run Amsoil, Castrol, Havoline, Quaker State, or Walmart oil. Your list of don'ts matches mine, except I also wouldn't run Rotella 5/40 because it has extremely high ZDDP, which allegedly can clog cats.
Let me see how to put this discretely..... clogged cats are no longer a problem for me.

Have you looked at the new Lucas and Kendall synthetics? I'm hearing excellent reports on their performance.
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Unread 07-24-2013, 07:47 PM   #54
Charley3
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Have you looked at the new Lucas and Kendall synthetics? I'm hearing excellent reports on their performance.
No. I've heard for years they have good conventional oils. This is the first I've heard of their synthetics.
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Unread 07-24-2013, 09:46 PM   #55
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I just got a new ScanGauge II a couple weeks ago. When I get my XJ back together, I'll unload all the tools from the back and see just what kind of mileage I can shake out of it. The best I ever did was 21 mpg stock on a 3-hour interstate run. I'll set my goal at 18 mpg for now.

I borrowed my wife's Escape to make a run over to my parents' place tonight and plugged the SGII into it just for fun. Cruise control, doing the speed limit and cycling the AC gave me 31 mpg each way. About 50/50 city and highway for that trip. I "accidentally" left the SGII hooked up so she can play with it tomorrow. She averages a little over 24 mpg when she drives it. Either way, for a 4-door 4x4 SUV, those are great numbers.
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Unread 07-24-2013, 10:16 PM   #56
Newtons3
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Quote:
Originally Posted by Charley3 View Post
No. I've heard for years they have good conventional oils. This is the first I've heard of their synthetics.
Three very well-known engine builders in this area have mentioned Lucas results on the dyno. Those empirical results should translate to economy also. I know Kendall from first-hand experience. Might be worth a look.
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Unread 07-25-2013, 06:53 AM   #57
StreckXJ
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So, if the fuel consumption comes from the mechanical fans turning as commanded by the thermostat....wouldn't the better choice be to go to electric fans rather than have the engine run at higher temps? There has to be a long (or maybe even medium) term trade off for running at higher temps for longer periods of time.
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Unread 07-25-2013, 08:54 AM   #58
Newtons3
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The controls we were all talking about were for electric fans. Within operational limits, running hotter is not detrimental. In fact, that is our point, it is actually better for the engine. Just remember, there is less headroom in the cooling capacity to absorb a glitch. Also, I think it is important to watch oil temps when raising op. temps.
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Unread 07-25-2013, 09:00 AM   #59
Billy
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interesting...
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Unread 07-25-2013, 09:37 AM   #60
Azzy
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Originally Posted by Newtons3 View Post
I check fuel mileage religiously on every vehicle I drive. It's a bit of an OCD for me. That said I always hate to quote a single tank. I have never found that ambient temperature of the fuel when I fill up makes any noticeable, trackable difference. In our state, the pumps are tested and regulated and you can be assured of their accuracy. The tolerance between pumps is negligible. Unless I've made some change to one of my Jeeps, the biggest factors affecting my fuel economy are average speed, air temp, a/c duty cycle, and humidity. Methanol as an oxygenate factors in, but that's purely mathematical.

Its been way back in the thread, but I wanted to comment on this. Fuel temps generally stay the same, since they are stored underground, well below the frost line. Us motorcycle guys always know that a fresh filled tank helps cool off the ... legs.... on a hot day. (then again, that might be from pumping too.. dunno)
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