Synthetics

[fredjacksonsan]

I had always read that using synthetics in your vehicle would increase your mpg. I had been skeptical until I finally tried it for myself.

In my 2000 Jeep Grand Cherokee, 4.0 six cylinder, auto, 4wd, I have seen about a 1.5 mpg increase after replacing every fluid (except axles, to be done soon) with synthetic lubricants. So mileage has risen from about 19 on the highway to 20.5 or so, and occasionally more.

Overall, doesn't seem like much; about a 7.8% increase. But I'll take it.

Is it worth the additional cost of the synthetics? Well, I can say that I've started having an oil analysis done at each oil change, and have found that I can go 7500 miles before changing the engine oil, which makes the synthetic about the same as the conventional oils in the long run when I factor in the cost of a good oil filter. I'm still experimenting and may eventually get a longer oil change interval, further increasing the benefit.

Over the course of the mileage between changes in the transmission and transfer case fluids, say 30K miles, I figure that (at $2.89 a gallon) I'm saving about $334 in gas costs.
(30K / 19 mpg = 1578 gal and $4563; 30 K / 20.5mpg = 1463 gal and $4229)

$334 is much less than the difference between the cost of conventional transmission fluids and synthetics.

So again, although the synthetics are more expensive to purchase initially, they do save $ by increasing gas mileage over the long run.

This savings will only increase as gas prices rise; and the use of synthetics also reduce the use of conventional, or "dino" oil.

So I'll say "Yes" to synthetics increasing your mpg. Every little bit counts.

[bluevp00]

Agreed. Synthetic not only increases MPG, but it also helps give you smoother performance and a lot better engine protection then dino oil.

[SaabJohan]

Synthetic lubricants can reduce friction. So will a thinner oil. I wouldn't expect any big gains though. For example ILSAC specified oils usually can decrease fuel consumption something like 1% compared to a reference oil.

[UncleBob]

I'd like to hear how synthetics reduce friction.

My understanding, synthetics are better because they have better heat breakdown properties and better shear properties. That will not effect power. That simply makes them have longer life and better motor component protection.

If you want to increase MPG using oils, go with a thinner oil. This reduces the amount of energy the oil pump needs to pump the oil. That is all that it will effect though.

If you want to go 300K miles on a motor, then you use synthetics. If you use longer oil intervals to take advantage of the synthetic heat break down qualities....then its pretty economical to use sythetics. Its what I use in everything I run. Not because I'm worried about mileage or power.....I've had enough engines apart, I've seen the benefits of synthetics. They do make a motor last longer, and thats a fact.

[CBFryman]

Synthetics are better for your engine as they lubricate better, with a good oil filter they can be run longer, they also clean your engine better. synthetics FTW.

[SR Racing]

I thought there was a sticky somewhere explaining some of the myths re: synthetic.

We have dyno tested (engine and chassis) several brands of synthetics and standard non-syth oils. For street use, you will not see any measurable gains of performance or decrease in fuel usage.

The ONLY exception to this is during the early stages of cold weather use. Comparable synthetics have a much better pour rate at low temps. After about 150 deg, you are hard pressed to see any differences.

By most measurements synthetic is better. (Especially in cold weather startups), and at above 260 degrees. (Since it still works at 300+ whereas petro oils have pretty much broken down.) But it's cost is probably not worth it on the street car.

We would be happy to measure temps, fuel consumption, HP, torque, or any other parameter you would like measured comparing synth and non-synth. Unless you are racing on the track you will see no real advantage.
We use synthetics in ALL of our race cars and standard oil in all our drivers. It is the best economic answer at this time.

BTW, we are currently doing indepedent testing on "MPG-CAPS" from Fuel Freedom International. They make some pretty wild claims and we have been asked to do the testing. We will be testing on the chassis dyno across 4 different vehicles. (Camry V6, Chevy LS V8, and two Ford V8's.
Fuel Flow, Temps, MAF, A/F, Torque and HP readings will all be taken on the dyno at about 6 different times per car. Nothing to do with oil, but I thought you might be interested. We will publish tests here if we get a chance. (Some of these tests will be owned by us (SR Racing) and some owned by the manufacture. His tests will not be public domain unless he allows it. However ours will be.

Jim
SR Racing

[cody_e]

Well I put some in and the knock my Neon had got a bit worse. I haven't noticed really any gas mileage improvements either.

[SR Racing]

Originally Posted by cody_e

Well I put some in and the knock my Neon had got a bit worse. I haven't noticed really any gas mileage improvements either.

You put what in your Neon? Synthetic oil or MPG-Caps?

Jim
SR Racing

[cody_e]

I put Mobile 1 Extended Performance in it.

[SR Racing]

Yes, I don't suppose you would get any noticable better mileage with synthetic.

If your "knock" is bearing related, I would expect that also, especially at lower temps.

Jim
SR Racing

[CBFryman]

Mobile 1 Full Synthetic increased my MPG by about 1mpg. but i was running on dirty oil before. It's been 7,000 miles and the oil still looks usably clean. I noticed a bit more pep after switching too.

[BlazerLT]

Just remember, there are only a few TRUE synthetics.

Most are Group 3 hydrocracked dino oils that through a legal loophole can be labelled synthetic.

True ones are:

Mobil1
Redline
Amsoil

All the rest are purified conventional oils, yet they screw you guys by charging the same price.

Be smart, get what you are supposed to get for your money.

Also, avoid Fram oil filters.

[SaabJohan]

Originally Posted by BlazerLT

Just remember, there are only a few TRUE synthetics.

Most are Group 3 hydrocracked dino oils that through a legal loophole can be labelled synthetic.

True ones are:

Mobil1
Redline
Amsoil

All the rest are purified conventional oils, yet they screw you guys by charging the same price.

Be smart, get what you are supposed to get for your moey.

Also, avoid Fram oil filters.

Motul are also synthetic. I think Shell also have some synthetic oils. There are most likely others aswell. Group 4 (PAO) and group 5 are real synthetic oils.

Group 3 oils are better than group 2 or 1 though.

If you buy semi synthetic you usually get only 10-20% syntetic oil.

[BlazerLT]

Originally Posted by SaabJohan

Motul are also synthetic. I think Shell also have some synthetic oils. There are most likely others aswell. Group 4 (PAO) and group 5 are real synthetic oils.

Group 3 oils are better than group 2 or 1 though.

If you buy semi synthetic you usually get only 10-20% syntetic oil.

Motul might be synthetic, but are really hard to find.

Shell oils are group 3.

[SaabJohan]

Originally Posted by BlazerLT

Motul might be synthetic, but are really hard to find.

Shell oils are group 3.

Motul is synthetic, group V. Red Line and Amsoil aren't easy to find either.

Newer Shell Helix Ultra are based on mostly group IV and V, but it does also contain some XHVI (wax isomerate).