Lighter oil 0w20 no better than 5w30 in my Corolla

[cdherman]

Just one personal observation, based on the last few weeks driving. I commute with a pretty predicatable route/combo of drving and temps.

Decided to put some 0w20 Mobil 1 in my 2006 1ZZ-FE Corrola to see if it would have better fuel economy than the PP 5w30.

I commute about 17 miles, but there are a few cold starts in there and I thought the 0w20 might do better in terms of mileage.

Well, the mileage is no different, worse if anything..... That is compared to last years mileage numbers.

That's over about 3k miles, carefully recorded. Not just one tank.

One disclaimer.... rumor has it that Missouri blenders are putting ethanol in the fuel without telling us. Might explain the mileage drop, I don't know. I am NOT bashing etoh, just acknowledging that it can drop the economy of some engines a tad.

 

[oilyriser]

I switched to 0w-20 last week from 5w-30 and can really feel the difference. MPG not yet measured, but soon will.

 

[BarkerMan]

With changing weather it's not a good time to grade mileage performance. Between your driving and the gasoline you buy it's got to be difficult to get repeatable performances from tank to tank.

 

[Titan]

not sufficient isolation of the myriad variables. It may or may not be more efficient in your car, but, the decreased viscosity cannot be held responsible for less fuel efficiency. One of more of the other non-isolated variables is resulting in less fuel efficiency.

 

[Bluestream]

You will get better MPG with the 0W20, thats just physics. Too many other variable going on for you to test this acurately at this time of year. Colder weather, winter grade gas, Ethanol...

 

[mitchcoyote]

His results still show how little difference a thinner oil makes in mpg.....

 

[mitchcoyote]

That 1zzfe is engineered for 5w-30......

 

[artificialist]

But later, Toyota issued a TSB saying that it was good to put 5w20 or 0w20 in those engines.

 

[Gary Allan]

The savings is seen more by those who have less miles per starting event. If you're doing a 30 miles commute ..you may see 1-2%. Easily masked by 30 seconds more idling here and there. Never get the oil warm for too long

..then you're dealing with multiples of the operating visc in DIFFERENCE between weights.

 

[CruzNlife1]

I was running castrol gtx(dino) 0w-20 I have a current mpg display in my truck. I noticed a small difference when I went to 5w-30 PP (worse mpg) I cruise 75mph on the highway each way to and from work. Same temps, same time of day, same driving style, at EXACTLY 75 mph each way. There was an average loss of .8 - 1.0 mpg after my oil change. For some reason though the truck gets better mileage towards the end of the OCI

My next change will be a synthetic 0w-20 Either amsoil signature, or something over the counter like M1. Unless they make that weight in PP From the reading I've seen on here, I'm going to be VERY happy sticking with PP.

 

[CruzNlife1]

Also measured a very small difference in mpg after the amsoil severe gear (75-90). I know for a fact that the diff is running much cooler, and I think that is keeping the viscosity higher (capacity is almost 3 qts too) I thought about thinning the rear diff just a tad with some amsoil mtf(5w-30 Transmission fluid) (like a 90/10 or 95/10 mix) Severegear/MTF

 

[Titan]

Originally Posted By: mitchcoyote
His results still show how little difference a thinner oil makes in mpg.....


No, his results show nothing. Too many other variables. I've driven 13,000 miles in the past two months, over almost identical terrain, at almost exactly the same speeds, and my mileage varies from a low of about 23 mpg to a high of 29.1 mpg. TOO MANY VARIABLES to tell anything about his change in efficiency. Not only is it tough to say we fill our tanks to exactly the same point, how do we know the fuel pumps are correctly calibrated? How do we know a spark plug is missing on every 1000th spark? How do we know wind direction, tire pressure, whether he hit the fourth traffic light or not? Etc. It may make no discernable difference due to the noise of all the other variables, or, it could be several percentage points difference. We do not know.

 

[Titan]

Originally Posted By: CruzNlife1

Also measured a very small difference in mpg after the amsoil severe gear (75-90). I know for a fact that the diff is running much cooler, and I think that is keeping the viscosity higher (capacity is almost 3 qts too) I thought about thinning the rear diff just a tad with some amsoil mtf(5w-30 Transmission fluid) (like a 90/10 or 95/10 mix) Severegear/MTF


I have a differential that is spec'd for 80-90. I have AmSoil 75-140 in it, and I average over the EPA highway fuel efficiency numbers on it, so, it must not be hurting mpg much. Then again, I only ran it with the factory 80-90 for a few thousand miles (it was a used car with 29,277 miles on it), so, I can't say there is no loss of mpg...

It would make sense that the smaller the engine, the colder the temps, and the more cold-runs, the more effect gear oil viscosity will have on fuel efficiency. Same with engine oil. Easily measurable? Yes, if you have the right set-up. Filling a tank at a gas station and watching the mpg for a few thousand miles isn't "the right set-up". You'd AT LEAST need a way to precisely measure fuel consumption.

 

[CruzNlife1]

I run a scangauge2 in my truck. Hooks up to the OBD-2 port, constantly measures and records any sensor in the motor. Also measures MPG, fuel consumption rate. Will read it out, per day, per tank, per week, current trip, last trip etc. I have it set to read out per tank. When I take my MPG estimates, I get on the highway, set the cruise at 75 on the way home(north) for 50 miles without touching or adjusting the cruise. I do it when the air intake temps and engine coolant temps are closest to 175/75* that seems to be the average. And hit reset, and as soon as I shut off cruise it will readout my actual MPG and fuel consumption for that cruise event.. I will drive home all week, the same time of the evening with identical conditions and only measure going north. Take my MPG at highway speed and than take the average of the 5 days. Thats how I come up with my numbers. Than when I make a fluid switch, I will do it again over 5 days and take the average. It went down when I went to the severegear, and it went down again when I went from 0-20 to 5-30. Between the severe gear and the heavier motor oil, I lost a total of 1.1 - 1.5 mpg.. I'm not saying they're bad fluids, the viscosity is higher. Than again I'm running a 4x4 truck on 31" tires with a 4 cylinder. It seems to be sensitive to the slightest things. It's a toyota it's got the overkill 8.4" rearend that holds 3 qts of fluid. I'm going to drive this truck forever.

Guys I've talked to on other forums, some reporting almost 400,000 miles so far with plain oil changes and fixing things if they break. The specific 4 cylinder that I have and the rearend has been proven bullet proof. No complaints with this particular transmission either.. This is my first toyota, best truck I've ever driven. (I dont tow or haul anything)

 

[CruzNlife1]

My truck came with the tall 4.30 gears. the 31" tires are stock on this truck. With the tall gearing, you can see my RPM/Speed ratio. One of the reasons I beleive in quality oil, I'm over 3000 rpm all the time. the dark pic above is driving home, and yes that's 5th gear, overdrive

 

[Bill in Utah]

You can not go by the Scan Gauge (or any other MPG readout) for accurate MPG data.

The only way is miles driven vs how many gallons you used.

OVER MANY TANKS!

I have the scan gauge and vehicles that have the MPG readout and everytime they are off. The scan gauge even after being calibrated is still off.

Take care, bill

 

[BarkerMan]

How is it that physics guarantee better performance going from 5w-30 to 0w-20? If in a given unknown engine the 5w-30 might supply a better ring seal leading to greater efficiency compared to a 0w-20 that pumps easier. I think that each situation offers enough variables to make a blanket statement like that difficult.

 

[CruzNlife1]

Originally Posted By: Bill in Utah
You can not go by the Scan Gauge (or any other MPG readout) for accurate MPG data.

The only way is miles driven vs how many gallons you used.

OVER MANY TANKS!

I have the scan gauge and vehicles that have the MPG readout and everytime they are off. The scan gauge even after being calibrated is still off.


Take care, bill


I have my calculator on the dash. Every fillup I measure gallons pumped vs. miles driven on the tank. I fillup at the same pump every time. And when it stops itself I pull it one time till it clicks. The scangauge is within .1 to .2 gallons every time. It has been very accurate. every fillup, you calibrate it. You hit the fillup button, and it will tell you how many gallons you've used. For example scangauge will say I've used 15.7 Gallons, the actual gallons pumped will be 15.61. You adjust the scangauge down to 15.6 from the fillup screen. Basically round to the nearest hundredth. There are times when it is dead on. Scangauge says I've used 12.8 gallons and I've pumped 12.77 or something close to that. The miles it reads by the end of the tank is extremely close to my trip. It doesnt use info from the odometer in the truck, it just shares the vehicle speed sensor. It will usually say I've driven 400 miles on the tank and my odometer says I've driven 399.8 Typically VERY close. It takes into account, intake temps, load, throttle position, speed, rpms, engine temp, etc... Has been very accurate

Also I had this in my 02 Lincoln LSE too. The lincoln had the factory mpg readout in the dash. That readout and the scangauge usually never matched. Guess which one was closer ((Hint: Probably not the factory display))

 

[Titan]

When there is a difference between the scan guage and the gallons pumped during a refill, how do you know which one was "off"? B-) You don't.

 

[Bill in Utah]

Originally Posted By: CruzNlife1
Originally Posted By: Bill in Utah
You can not go by the Scan Gauge (or any other MPG readout) for accurate MPG data.

The only way is miles driven vs how many gallons you used.

OVER MANY TANKS!

I have the scan gauge and vehicles that have the MPG readout and everytime they are off. The scan gauge even after being calibrated is still off.


Take care, bill


I have my calculator on the dash. Every fillup I measure gallons pumped vs. miles driven on the tank. I fillup at the same pump every time. And when it stops itself I pull it one time till it clicks. The scangauge is within .1 to .2 gallons every time. It has been very accurate. every fillup, you calibrate it. You hit the fillup button, and it will tell you how many gallons you've used. For example scangauge will say I've used 15.7 Gallons, the actual gallons pumped will be 15.61. You adjust the scangauge down to 15.6 from the fillup screen. Basically round to the nearest hundredth. There are times when it is dead on. Scangauge says I've used 12.8 gallons and I've pumped 12.77 or something close to that. The miles it reads by the end of the tank is extremely close to my trip. It doesnt use info from the odometer in the truck, it just shares the vehicle speed sensor. It will usually say I've driven 400 miles on the tank and my odometer says I've driven 399.8 Typically VERY close. It takes into account, intake temps, load, throttle position, speed, rpms, engine temp, etc... Has been very accurate

Also I had this in my 02 Lincoln LSE too. The lincoln had the factory mpg readout in the dash. That readout and the scangauge usually never matched. Guess which one was closer ((Hint: Probably not the factory display))



Never mind. I own one (a Scan Guage II). It is a nice unit but ANY MPG gauge is not going to be accurate.

Again, You take the miles (once you take in account the odo error) divide actual gas used over MANY tanks.

Go ahead and use your gauge.

I like real data.

We will agree to disagree.

Bill