Over thinking engine oil - MPG related

[Loobed]

Originally Posted By: SrDriver

We experience long hot Summers here in south Alabama and all I know is the Ford Police Cars here run 5W20 oil and you know the abuse they receive.

Are the Fords speced for 20w or 30w?

 

[Artem]

All Fords minus the Turbo models spec 20 grade for 2011.

 

[CATERHAM]

Originally Posted By: Artem

i don't know what to say to that. I called Redline and the tech told me 5w30 is what i need for my Modified K series engine. I don't understand all the HTHS cP viscosity ratings but if is says 5w20 on the bottle, i take it as a 20 grade (it can be on the quick or thin side of things, its still a 20 grade at the end of the day (or will shear down into it within a few miles on use)) and hence, labeled as such. I'm not experimenting with oils based on the HTHS cP rating but based on what's on the bottle. What Honda originally spec'd for the engine doesn't apply to me because my engine is modified and produces more power then the stock rating. I'm also not interested in using a thin 30 grade for MPGs sake. I'm interested in good engine protection while spinning the engine to 8,600 RPM while still trying to maintain decent gas mileage. Seeing as both M1 and Amsoil's best sheared into a thick 20 grade, its no good to me.

The SAE didn't take ester based oils into consideration when they derived the oil grading system and they still don't as they constitute a drop in the bucket. There should be a HTHS maximum for an SAE grade but there isn't and that's why the system doesn't work very well with RL. But if you read the back of the RL 5W-30 bottle it basically tells you the oil is a 40wt when it says it has a "higher in bearing viscosity than most petroleum 10W40s". But the point you're really missing is that the oil grade on the bottle is not important, it's operational viscosity that is and only an oil pressure gauge will tell you what it is at any given time when the engine is running. If you have a modified engine you should have an OP gauge.

 

[WMSmotorhead]

Originally Posted By: needsducktape

When did Ford do the big switch to 5-20?

Rumor mill says better machining... tighter tolerances. I usually pour what the car says to use... lots of 5-20 in my garage with a 5-30 hanging around for the guest cars that come by for service. To eek out MPG, I agree that driving style is a big one... Tires, and a Clean fuel, air and crankcase. If the car is clean and well lubed, you will usually hit your pinnacle. I've also found that fuel grade matters a bit too... 89 will give better mpg than 87 by a little margin... Enough to grant an extra 20 miles out of the tank and offset the extra cost into a 2$ savings.

 

[OVERKILL]

Originally Posted By: Artem

All Fords minus the Turbo models spec 20 grade for 2011.

The BOSS 302 spec's 5w50, as does the GT500.

 

[Artem]

Originally Posted By: WMSmotorhead

I usually pour what the car says to use... lots of 5-20 in my garage with a 5-30 hanging around for the guest cars that come by for service. To eek out MPG, I agree that driving style is a big one... Tires, and a Clean fuel, air and crankcase. If the car is clean and well lubed, you will usually hit your pinnacle. I've also found that fuel grade matters a bit too... 89 will give better mpg than 87 by a little margin... Enough to grant an extra 20 miles out of the tank and offset the extra cost into a 2$ savings.

Thank you for the post regarding the original topic.

 

[Artem]

Originally Posted By: CATERHAM

Originally Posted By: Artem

i don't know what to say to that. I called Redline and the tech told me 5w30 is what i need for my Modified K series engine. I don't understand all the HTHS cP viscosity ratings but if is says 5w20 on the bottle, i take it as a 20 grade (it can be on the quick or thin side of things, its still a 20 grade at the end of the day (or will shear down into it within a few miles on use)) and hence, labeled as such. I'm not experimenting with oils based on the HTHS cP rating but based on what's on the bottle. What Honda originally spec'd for the engine doesn't apply to me because my engine is modified and produces more power then the stock rating. I'm also not interested in using a thin 30 grade for MPGs sake. I'm interested in good engine protection while spinning the engine to 8,600 RPM while still trying to maintain decent gas mileage. Seeing as both M1 and Amsoil's best sheared into a thick 20 grade, its no good to me.

The SAE didn't take ester based oils into consideration when they derived the oil grading system and they still don't as they constitute a drop in the bucket. There should be a HTHS maximum for an SAE grade but there isn't and that's why the system doesn't work very well with RL. But if you read the back of the RL 5W-30 bottle it basically tells you the oil is a 40wt when it says it has a "higher in bearing viscosity than most petroleum 10W40s". But the point you're really missing is that the oil grade on the bottle is not important, it's operational viscosity that is and only an oil pressure gauge will tell you what it is at any given time when the engine is running. If you have a modified engine you should have an OP gauge.

Hmmmm.... thank you for giving me something to think about. I'll wait for the UOA report to come in by the end of this week and see the results from that before moving forward (plan to pull a sample from the oil pan without draining the sump) My engine modifications consist of improving upon what Honda originally designed by increasing air flow coming in and outta the engine as well as cooling system upgrades to help control engine temps and a full dyno tune to bring it all together. I haven't had the NEED to monitor oil pressure just yet as i have not cracked open the block to upgrade cams, higher compression pistons, etc etc. Its definitely a must in the future, i gotta agree. Time will tell.

 

[TFB1]

Originally Posted By: WMSmotorhead

Originally Posted By: needsducktape

When did Ford do the big switch to 5-20?

Rumor mill says better machining... tighter tolerances.

Do you mean tighter clearances??? Tolerance is the amount of difference from minimum to maxim clearance... If the tolerance is tighter, that just means the clearances are kept to more of a optimum spec and not a little tight or loose... Ford has now back spec'd many engines saying the 5w-20 oils are OK, so much for the better machining on the newer engines... As far as going to a lighter oil in a higher mileage engine, that no doubt now has some wear and larger clearances than orig, I don't see it as a good idea...

 

[Artem]

Originally Posted By: TFB1

Originally Posted By: WMSmotorhead

Originally Posted By: needsducktape

When did Ford do the big switch to 5-20?

Rumor mill says better machining... tighter tolerances.

Do you mean tighter clearances??? Tolerance is the amount of difference from minimum to maxim clearance... If the tolerance is tighter, that just means the clearances are kept to more of a optimum spec and not a little tight or loose... Ford has now back spec'd many engines saying the 5w-20 oils are OK, so much for the better machining on the newer engines... As far as going to a lighter oil in a higher mileage engine, that no doubt now has some wear and larger clearances than orig, I don't see it a a good idea...

 

[WMSmotorhead]

Yeah, I meant clearances. Honda and Ford are the ones calling for 5-20.. The owners manual says 5-30 is OK if that's all you can get. For awhile I rad 5-30 in my focus cars (2 of them) until a good generic 5-20 was out.

 

[CROWNVIC4LIFE]

Originally Posted By: TFB1

Ford has now back spec'd many engines saying the 5w-20 oils are OK, so much for the better machining on the newer engines... As far as going to a lighter oil in a higher mileage engine, that no doubt now has some wear and larger clearances than orig, I don't see it as a good idea...

When I had my [99] 4.6 G.M.Q. I ran 5W30 Dino Motorcraft for the first 90K miles..The car used 1 quart every 4500 miles..I did 5K mile OCI'S..Then Ford went to Motorcraft Synthetic Blend..From 90K mies to 220K miles I ran 5W20 Motorcraft Synthetic Blend..The car used zero oil on the 5W20 Motorcraft Synthetic Blend doing the same 5K miles OCI'S..That is in jungle heat and nightmare traffic..Go figure. I was very hesitant on using the 5W20 at first but after my first 5W20 run which included a trip to Key West in 95 degree heat in nightmare traffic along US-1 [a/c was on the entire time] I quickly changed my mind. Hurricane Wilma totaled the car out on me in 2005 or I would still have it.

 

[Artem]

Strange indeed. Perhaps the synth blend was simply burning off less (or non at all) nonetheless, interesting review. Did you notice any gas mileage increase?

 

[CROWNVIC4LIFE]

Originally Posted By: Artem

Did you notice any gas mileage increase?

No..Mileage stayed the exact same which was 26 MPG on the highway and around 16.5 in local stop and go..The a/c stays on all the time. The [05] 4.6 Vic I got now [110K miles] gets the same mileage using the same Motorcraft oil.

 

[Whimsey]

Originally Posted By: needsducktape

When did Ford do the big switch to 5-20?

My 2002 F-150 with the 4.6 V-8 specs 5W-20. My friend had a 2001 F-150 with the 4.6 and I think his spec'd 5W-30, though not positive. Whimsey

 

[CROWNVIC4LIFE]

Originally Posted By: needsducktape

When did Ford do the big switch to 5-20?

As I recall it was around March 2002.

 

[EchoThat]

From Artem - 5/30/11 "First off, the car you're driving is pretty much maxed out, as far as fuel economy is concerned (Lets not count the fact that an auto manufacturer will detune an engine to produce worse gas mileage, while still better then the previous model year, because lets face it, if they give you the best they can do today, it will be hard for them to beat that tomorrow when the next model is introduced - but that's a whole other subject better left for tomorrow's conversation)" I saw a segment on a show a few years ago, no idea what show it was, about just this. A company in California does re-programming on your car's computer to allow the vehicle to work to its potential, instead of functioning at the everyday mediocre performance level that is passed off as top of the line. I haven't heard anythging about anyone doing this since. I imagine that it still goes on, however. There is definitely a market for it.

 

[Whimsey]

Originally Posted By: CROWNVIC4LIFE

Originally Posted By: needsducktape

When did Ford do the big switch to 5-20?

As I recall it was around March 2002.

My 2002 F-150 was built in October of 2001 and it spec'd 5W-20 in the owner's manual. Whimsey

 

[Artem]

Originally Posted By: EchoThat

From Artem - 5/30/11 "First off, the car you're driving is pretty much maxed out, as far as fuel economy is concerned (Lets not count the fact that an auto manufacturer will detune an engine to produce worse gas mileage, while still better then the previous model year, because lets face it, if they give you the best they can do today, it will be hard for them to beat that tomorrow when the next model is introduced - but that's a whole other subject better left for tomorrow's conversation)" I saw a segment on a show a few years ago, no idea what show it was, about just this. A company in California does re-programming on your car's computer to allow the vehicle to work to its potential, instead of functioning at the everyday mediocre performance level that is passed off as top of the line. I haven't heard anythging about anyone doing this since. I imagine that it still goes on, however. There is definitely a market for it.

I also remember seeing/reading about that as well a few years back. My 07 Civic Si is tuned for Max Power in 1st-5th gear but the air/fuel ratio in 6th is extremely leaned out to maximize gas mileage on the highway. Works VERY well with the scan gauge reading close to 40 MPG @ 65-70mph with cruise control on, on a car rated for 29 MPG highway. It's funny. The car makes more power then stock and get better gas mileage at the same time. It's amazing.

 

[A_Harman]

Originally Posted By: friendly_jacek

One more thing: how come the 18 wheelers are still using 15W40 and not 5W20?

That's an easy one: their engines are designed for oils which have 3.5 min HTHS viscosity. There's a reason they're called heavy duty engines. They work hard all the time. And if you have ever looked at bearings that come out of an engine with 600,000 miles on it, you would understand why thin oil is just not used.

 

[demarpaint]

Originally Posted By: Whimsey

Originally Posted By: CROWNVIC4LIFE

Originally Posted By: needsducktape

When did Ford do the big switch to 5-20?

As I recall it was around March 2002.

My 2002 F-150 was built in October of 2001 and it spec'd 5W-20 in the owner's manual. Whimsey

My 93 Aerostar was back spec to 5W20, IIRC 93 was the cut off, 92 still calls for 5W30. Anyway using 5W20 reduced oil use for me. Now that I have some leaking issues I mix and match. Not all Ford engines were back spec'd so you'd have to search the www and see which ones were back specd. I recall seeing a list. HTH