Full Synthetic Oil

[Drawbar]

I was told that if you change all the oil in your truck to full synthetic oil (Tranny, rear-end, front-end, tranny, transfer case, etc) you could get another two miles more per gallon out of your truck. Back when I worked for the railroad and only traveled 50 miles a day, I was not to concerned about fuel economy, but with gas creeping up there in price, and my commute close to 100 miles per day, well its starting to look promising.

Is this purely blarney, or is this a legitimate claim? Any thoughts?

[systech1]

I did this to my 2001 F250 a couple of years back and did not notice any measurable improvement. The only way I can get my gas mileage up is to leave a little earlier to avoid avoid traffic and drive slower. At 75mph I get 13mpg. at 60mph 15.5mpg. At $3.00 a gallon I leave early and drive slower.

[Ingersoll444]

I have done it on my 4WD's and found it a LOT better. BUT!! Only in the cold wether, and mostly when used for short trips. There is a lot of thick, heavy gear lube in all them cases, and the synth flows a LOT Real gear lube, but still. So my advice is if you are due for a fluid change anyway, do it. Your not going to lose out, but you will only see a difference on the cases that use gear lube, and durning the first few miles in real cold wether.

[jdkubotamurray]

I have done it on my 4WD's and found it a LOT better. BUT!! Only in the cold wether, and mostly when used for short trips. There is a lot of thick, heavy gear lube in all them cases, and the synth flows a LOT Real gear lube, but still. So my advice is if you are due for a fluid change anyway, do it. Your not going to lose out, but you will only see a difference on the cases that use gear lube, and durning the first few miles in real cold wether.
The additional benefiot is reduced wear and improved temp protection

[glenn27]

I changed over to full synthetic in my Toyota 4wd p/up about 8 months ago---gears oils about four months ago--just sent an oil sample away to be tested...

Manufacturers est. miles/ per gal on my truck are 17-19 highway....I get 21-22.5, and 75% probebly of my driving is interstate....
The thing is I have extended my service intervals...which saves my ol' back a little strain.....
So far I'm very happy-I feel like I have already recouped the initial higher cost, and outlay, as my time has to be worth something :fing32: .....I still check everything on a weekly basis, though......

[MikeC]

I have a Subaru that has full, 100% PAO synthetics throughout (think Amsoil and Redline, not the Wal-Mart group III). Mileage rating for it is 30MPG highway, I average between 33 and 34 as registered on my scangauge. If you're not familiar with a scangauge, it's an aftermarket device that plugs into the ODBII port, pulls information from the computer and displays it.

Even if you switch, will you make up enough to cover the costs of a full synthetic? Probably not, unless you also practice extended OCI's (Oil Change Intervals). I run ~10,000 miles on my wifes Jeep, 7000 on my Subaru (until the warranty period is over), and ~7000 on my Z (engine oil). Once I'm out of warranty on the Subaru it will get extended to 10-15K miles depending on what the used oil analysis dictates.

In all honesty you'd probably not save enough to really make it worth it in a full size 12 MPG 4X4 pickup. However an investment in a smaller commuter vehicle would probably save enough to justify the cost. You can find some of the 3-4 year old GM products dirt cheap right now (watch the famous intake manifold gasket), 2-3 year old Hyundia's and Kias are excellent cars (troublesome automatic transmissions if not serviced) and sell dirt cheap as well. Nissan Sentras can be had cheaply too and they run forever.

[Ingersoll444]

The additional benefiot is reduced wear and improved temp protection


Yes, that is true, and thats why I use it in my gear boxes.

[bigl22]

I have been using Mobil I in my cars for about 5 years now-- wife's nissan 2002 altima runs quieter and slightly cooler-- gets ok mpg[ 30-34]- I use it and a mobil I filter on my dodge dakota I carry the mail in-- much quieter in it -- I change when it turns dark brown[ about 5K miles on nissan and about 3 months for truck-- I run my truck for 5 hours/day at speeds from idle to 60mph -- stop about every 50 yards average -- if I drove in hiway 5 hours/day at 60mph I would put 300 miles/day on that truck -- only thing that he;lped MPG was to have front end of truck re-aligned -- factory seting was way off-- [ -3 to +16 ] went from 9mpg to 10 mpg-- about 17.7 just driving it around[ 4x4 extended cab-- heavy rear end etc.] synthectic tranny fluid helped shifting quite a bit -- bigl22

[Drawbar]

Currently I run full-synthetic in my engine and extended my oil changes up to 7 thousand miles. I have no issues with any of that, I was just curious really if running synthetic oil in my drivetrain would help out on the fuel economy.

By the way though. One thing I have learned about Full-Synthetic oil is that you can not go by its color. It does not break down like mineral based oil, but that does not mean the oil is not picking up contaminents. The only real way to tell if your oil is good or not is with a viscosity/ contamination check.

[draddogs]

I take that would be an added expense on top of the extra price for the oil. I like to see it darken and change more often. I also don't believe that it is more conduceive to longer metal life if oil is changed on a regular basis. That is the real problem with most people, they dont pay any heed. jmo

[draddogs]

.

Nissan Sentras can be had cheaply too and they run forever.

But they are butt ugly ROF

[Ingersoll444]

But they are butt ugly ROF


LOL!! You know my sisterin law has one of the top of the line SER specV cars. Looks like every other small car on the road. GREAT car, and goes good though. I dont think I would call it ugly. Just no soul.

[MikeC]

By the way though. One thing I have learned about Full-Synthetic oil is that you can not go by its color. It does not break down like mineral based oil, but that does not mean the oil is not picking up contaminents. The only real way to tell if your oil is good or not is with a viscosity/ contamination check.

The "color" of any engine oil, conventional or synthetic, is meaningless. Different manufacturers use different dyes and additive packages that react differently to heat, as well as the base oil used. Engine oil that turns dark quickly simply only means that the additive package or base oil is reacting to the heat of the engine. Nothing more.

Your filter picks up the contaminents in both conventional and synthetic oils.

I also agree with your thoughts on a Used Oil Analysis. Especially in cases where extended oil change intervals are being practiced, a UOA with TBN (Total Base Number) can give you insight into how the oil is holding up in a particular application, especially in applications where the engine is especially brutal on the oil.

A UOA can also spot trouble before it becomes an issue. I've had a couple friends who have discovered head gasket or intake manifold leaks by doing a UOA.

Here's a copy of my last UOA on my Z if you've never seen one before. The fuel dilution mentioned was caused by a leaking injector (since replaced). I didn't know I had an injector problem until I recieved this report. As you can also see, the Amsoil brings the wear metals down well below the universal averages.

http://i34.photobucket.com/albums/d127/chiodorm/Zreport.jpg

[Ky Greg]

How and where can you have your vehicle tested and what's the cost? Thanks, greg

[LilysDad]

Back when they first came out with synth., the common thought was if you used it in a motor that was already using motor oil, it would 'loosen up' (clean out deposits) and start burning oil. Has this been the case with anyone?

[glenn27]

How and where can you have your vehicle tested and what's the cost? Thanks, greg

I get mine done thru The CAT dealer here---my son is a field technician for them....they're deal is you buy the "little kit"..drain bottle/ hose etc. for $15, label what is is---mileage/hours /type of oil, etc/...take it in--here they send it to their headquaters in Salem, Va.--a week or so later/they mail you results---if you have a serious problem--they will call you first day, and fax , if for example, water in oil, etc....

:fing32: If you need or want a second opinion--they will send away to Mobil Oil for comparison...

[MikeC]

How and where can you have your vehicle tested and what's the cost? Thanks, greg

I use Blackstone Labs (http://www.blackstone-labs.com/) and have been very satisfied with them. The cost runs about $20 or so per analysis. I purchase mine in bulk so it's a bit less.

Blackstone also partners with Terry Dyson. If there is a problem, Terry will read the analysis (for a small fee) and tell you what the problem is.

I've had a couple people find leaking head gaskets and get them repaired before there was a real problem simply by having a UOA done.

I've also changed a couple habits based on my UOA's.