My MPG took a S#$T!
Thread Starter
Newbie
Joined: Feb 2014
Posts: 22
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From: South florida
My MPG took a S#$T!
I have been a creeper on these forms for SEVERAL months and i have gotten all my answers VIA Search.. But this one i cannot find an answer for.
TO make a long story short, i have been using 10w30 for the length of the car since i lived in south florida and rarely got cold all year long. Recently, i have moved further up north where temps reach a Low of 40-50's so i switched to 5w30 recently for my oil change.
Since then my MPG took a damn **** on me from my consistent 19-22. Nods include intake and stage 1 tune. otherwise DS. Fully synthetic oil ONLY and i have changed the oil myself each time.
could the low temps cause my terrible MPG? I'm only getting 13-15 mpg WITH grandma driving. after 4-5 tanks of gas
TO make a long story short, i have been using 10w30 for the length of the car since i lived in south florida and rarely got cold all year long. Recently, i have moved further up north where temps reach a Low of 40-50's so i switched to 5w30 recently for my oil change.
Since then my MPG took a damn **** on me from my consistent 19-22. Nods include intake and stage 1 tune. otherwise DS. Fully synthetic oil ONLY and i have changed the oil myself each time.
could the low temps cause my terrible MPG? I'm only getting 13-15 mpg WITH grandma driving. after 4-5 tanks of gas
sounds normal to me. MY previous MR does the samething after I moved from LA to Nebraska.
I think it is just that cold weather increase the gas injection when car is cold.
How long is your drive each session usually?
If it less than 20 mins each session, then it is definitely gona suck gas.
I think it is just that cold weather increase the gas injection when car is cold.
How long is your drive each session usually?
If it less than 20 mins each session, then it is definitely gona suck gas.
Thread Starter
Newbie
Joined: Feb 2014
Posts: 22
Likes: 1
From: South florida
Thank you everyone for your input, But i havent changed a thing except my oil from 5w to 10w. Mind you, when i moved i still had 10w30 in my car for a few months and got the good MPG. When i changed from 10w to 5w is when i noticed a changed BUT consider that when i changed to 5w is when it STARTED getting cold.
I only have a conservative stage 1 cobb tune with intake only and my commutes are always < 15 mins. but my MPG was not terrible entire time. same brand of oil aswell. No issues with the car otherwise. still holding peak boost and such. no alignment issues. all brand new tires
I only have a conservative stage 1 cobb tune with intake only and my commutes are always < 15 mins. but my MPG was not terrible entire time. same brand of oil aswell. No issues with the car otherwise. still holding peak boost and such. no alignment issues. all brand new tires
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Evolving Member
Joined: Jul 2014
Posts: 151
Likes: 1
From: PA
If you are using pure synthetic the oil is nearly identical. There was a study a while back saying pure synthetic is actually all the same within certain weight classes. Not sure if there's any legitimacy to it, but if there is, then the oil isn't to blame. Here's some snippets from a Google search:
...
The take away from all this is basically:
So my question is now: Why did you switch oil weights?
Edit: Source: http://www.bobistheoilguy.com/motor-oil-103/
Edit 2: Mobil 1's MPG oil only comes in 0w20 and 0w30. They say this is fine for any engine, in any temperature. That's because the first number is basically irrelevant for synthetic oil. That's one of the reasons for why we like synthetic oil. Source: http://www.mobiloil.com/USA-English/...l_Economy.aspx
Edit 3: You moved, your MPG went down. You switched oil weights, but it honestly shouldn't matter. Did you check your tire pressure? Lower temps = lower pressure. Did your type of commute change? Are there more hills? More stopping/starting? Etc. Are you getting good gas? Try getting gas somewhere else. There's a few places near me where I take an MPG hit around 5-10mpg if I get gas there no matter what car I drive.
Edit 4: Just an FYI, it was 34F here the other night and I got 18 MPG driving it like it's an Evo. So if you wanted some support for "It's not the temp" there you go.
A 10W-30 multi-grade mineral based oil is made from a 10 grade oil and has VI improvers added to thicken the product in a 212°F engine. It acts as a 30 grade oil when hot. It acts more as a 10 grade oil at startup. I remind you that a 10, 5 or 2 grade oil is still too thick to provide lubrication at startup. They are all too thick at startup. There is currently no engine oil thin enough to operate correctly at startup. They all cause excessive wear at startup. Again, we are discussing the needs of my single hypothetical engine for around town driving.
Let’s look at the make up of synthetic based oils. A 10W-30 synthetic oil is based on a 30 grade oil. This is unlike the counterpart mineral oil based on a 10 grade oil. There is no VI improver needed. The oil is already correct for the normal operating temperature of 212°F. It has a thickness of 10 while you drive to work. It will never thin yet has the same long term problem as the mineral based oil. They both thicken with extended age.
Let’s look at the make up of synthetic based oils. A 10W-30 synthetic oil is based on a 30 grade oil. This is unlike the counterpart mineral oil based on a 10 grade oil. There is no VI improver needed. The oil is already correct for the normal operating temperature of 212°F. It has a thickness of 10 while you drive to work. It will never thin yet has the same long term problem as the mineral based oil. They both thicken with extended age.
A synthetic oil that is labeled as 10W-30 is less honey like as a mineral based 10W-30 motor oil at startup. They both have a thickness of 10 at normal operating temperatures. At 75°F the synthetic is not as thick. At 32°F the difference between the two is even greater. At 0°F the mineral oil is useless yet the synthetic works fairly well. Just keep the RPM to a minimum.
At temperatures below zero you will not be able to start your car with mineral oils while the synthetic oils may be used to -40° or -50°F. Oils are so thick that the normal method of viscosity measurement is not possible. Instead we measure if the oil can even be pumped or poured. Again, we are only discussing a single category of oil, the multi-grade 10W-30 API / SAE grade.
At temperatures below zero you will not be able to start your car with mineral oils while the synthetic oils may be used to -40° or -50°F. Oils are so thick that the normal method of viscosity measurement is not possible. Instead we measure if the oil can even be pumped or poured. Again, we are only discussing a single category of oil, the multi-grade 10W-30 API / SAE grade.
To recap, synthetic oils have similar characteristics as mineral oils at operating temperatures. The synthetic oil will however be less honey – like at startup even though it has the same API / SAE rating. Yet the synthetic 10W-30 grade oil is based on a heavier 30 grade oil while the mineral based 10W-30 oil is based on a thinner 10 grade oil. They are both similar at operating temperatures yet the 30 grade based synthetic is actually less thick at startup and much less honey – like at low temperatures. This is the opposite of what common sense dictates.
Edit: Source: http://www.bobistheoilguy.com/motor-oil-103/
Edit 2: Mobil 1's MPG oil only comes in 0w20 and 0w30. They say this is fine for any engine, in any temperature. That's because the first number is basically irrelevant for synthetic oil. That's one of the reasons for why we like synthetic oil. Source: http://www.mobiloil.com/USA-English/...l_Economy.aspx
Edit 3: You moved, your MPG went down. You switched oil weights, but it honestly shouldn't matter. Did you check your tire pressure? Lower temps = lower pressure. Did your type of commute change? Are there more hills? More stopping/starting? Etc. Are you getting good gas? Try getting gas somewhere else. There's a few places near me where I take an MPG hit around 5-10mpg if I get gas there no matter what car I drive.
Edit 4: Just an FYI, it was 34F here the other night and I got 18 MPG driving it like it's an Evo. So if you wanted some support for "It's not the temp" there you go.
Last edited by Ancyker; Nov 3, 2014 at 04:57 PM.
Thread Starter
Newbie
Joined: Feb 2014
Posts: 22
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From: South florida
Okay thank you for that informative piece you have posted. now i can eliminate the Tmp idea. the reason why i changed oil grades is becuase i assumed it would be a lot colder where i am and i wanted to help protect my engine from cold start damage.
UPDATE: i just realized that i have a lot of extra oil in my car.. maybe more than a quart. i think im at 6 quarts. going to drain oil right now and update.
P.S the bad gas idea makes sense also becuase of course when i changed my oil, i started using a new gas station since it was cheaper. ill investigate further
UPDATE: i just realized that i have a lot of extra oil in my car.. maybe more than a quart. i think im at 6 quarts. going to drain oil right now and update.
P.S the bad gas idea makes sense also becuase of course when i changed my oil, i started using a new gas station since it was cheaper. ill investigate further
Evolving Member
Joined: Jul 2014
Posts: 151
Likes: 1
From: PA
Okay thank you for that informative piece you have posted. now i can eliminate the Tmp idea. the reason why i changed oil grades is becuase i assumed it would be a lot colder where i am and i wanted to help protect my engine from cold start damage.
UPDATE: i just realized that i have a lot of extra oil in my car.. maybe more than a quart. i think im at 6 quarts. going to drain oil right now and update.
P.S the bad gas idea makes sense also becuase of course when i changed my oil, i started using a new gas station since it was cheaper. ill investigate further
UPDATE: i just realized that i have a lot of extra oil in my car.. maybe more than a quart. i think im at 6 quarts. going to drain oil right now and update.
P.S the bad gas idea makes sense also becuase of course when i changed my oil, i started using a new gas station since it was cheaper. ill investigate further
I get mine at Shell, it seems pretty good. Sheetz also seemed alright, but I eventually settled with Shell. I wanted to go with Sheetz since it's a local business, but the Shell just seemed better. That part might be in my head, but the one Exxon near here is not. I thought it might be until I talked to others with similar problems. I also get my heating fuel from Shell so I can score a discount on gas sometimes. Switching where you get gas can have a big impact though, and it's most likely your issue.
MPG goes down slightly in the winter because of a lot of factors. It's usually not super significant unless your commute is pretty short. EPA has info:
- Engine and transmission friction increases in cold temperatures due to cold engine oil and other drive-line fluids.
- It takes longer for your engine to reach its most fuel-efficient temperature. This affects shorter trips more, since your car spends more of your trip at less-than-optimal temperatures.
- Heated seats, window defrosters, and heater fans use additional power.
- Warming up your vehicle before you start your trip lowers your fuel economy—idling gets 0 miles per gallon.
- Colder air is denser, increasing aerodynamic drag on your vehicle, especially at highway speeds.
- Tire pressure decreases in colder temperatures, increasing rolling resistance.
- Winter grades of gasoline can have slightly less energy per gallon than summer blends.
- Battery performance decreases in cold weather, making it harder for your alternator to keep your battery charged. This also affects the performance of the regenerative braking system on hybrids.
In severe winter weather, your mpg can drop even further.
- Icy or snow-covered roads decrease your tires' grip on the road, wasting energy.
- Safe driving speeds on slick roads can be much lower than normal, further reducing fuel economy, especially at speeds below 30 to 40 mph.
- Using four-wheel drive uses more fuel.
Source: http://www.fueleconomy.gov/feg/coldweather.shtml
